BigTokes ~ Basic Water Chemistry!!

Due to the overwhelming response about the use of {H20} I have decided to make this post that was and is in my grow thread (AK-47 & HDF Side By Side Bio-Bucket Style!!!) documention it’s own thread, enjoy!!


Ok, well now let’s get this thing started!!

Let’s speak for a moment about what I feel that is mostly every ones problems with (pH), as I have said before every hydroponics system wither it is store bought or (DIY) must be built around two things!!

• (water efficiency) the supply, demand, and runoff thereof.
• utilization of (Dissolved Oxygen). This is, supply, exchange, and replenish.

if you have built or bought your system around these principles, then your next step would be (water analysis), simply put this means (Head or Soft Water?) The main difference between (Hard and Soft water) is hard water contains much more dissolved minerals – calcium and magnesium, for example – than soft water does.

Now that you’ve determined that your water type let’s say is (Hard). Hard water forms when naturally occurring minerals enter water sources. Over time, these minerals are absorbed by groundwater. The two most common types of minerals found in hard water are calcium and magnesium compounds. The term "hard water" was originally coined to refer to water that was difficult to work with. Hard water requires much more soap, shampoo or detergent than soft water, so your soap products don't stretch nearly as far. The effects of hard water are felt most often in daily household activities such as cleaning. The minerals present in hard water inhibit soap's lathering and cleaning capabilities.

All that means is, your water has a certain amount of (calcium and magnesium) in the water, now the way you determine this is by the ppm’s, they tell you how much (GH) are in the water, btw I think most of us already know this but I will say it again, your ppm meter is mostly reading the (GH) of your hydro-systems solution, the reason for this is that calcium and magnesium are the two larger atoms in your water/solution and therefore the most conductive mineral/element of all. According to the U.S. Geological Survey, more than 85 percent of the United States geography has hard water. I have noticed that a lot of growers use water softeners. Water filtration systems come in many forms. I will discuses this later on.



The next step would be for you is to understand what that means to you as a hydroponics grower in a long term recirculating system such as the Bio-Buckets. Hard water is characterized by high levels of Bicarbonates and it makes itself known in the form of calcium and magnesium. Hard water will usually have a high pH but not necessarily, this will depend on the alkalinity of your water source, this is the reason I recommend using tap-water because it has been treated to have the most stable levels of alkalinity and by using any form of water filtration system you have there by destabilized your water alkalinity levels among other things, and thereby will not hold up under long term recalculating growing conditions, but on the other head great for drinking water but were not trying to produce good drinking water for your Bio-System, were trying to produce the best stabilized water possible and the alkalinity levels tell you what that is……..are we begging to see the light yet? Well if not, don’t worry were not done yet!!!

The obvious problem for the grower is that he will be adding quite large amounts of acid on a regular basis. If using Phosphoric acid this may lead to a build up of Phosphate in the reservoir over time. High levels of P in the solution can inhibit the uptake of other salts, Zinc for instance, and cause general nutrient imbalance.

1. The first and most obvious solution is to change-out or flush regularly. This will reduce the chances of Phosphate accumulation and ensure maintenance of a good nutrient profile. Frequency of changes-outs or flushes truly depend on the volume of water/nutrient reservoir size and number of plants. In very Hard water arias however a large amount of Phosphoric acid will be needed to correct (pH) when nutrient is first made up.
2. The Best Solution by far is to use a specific formulation which is usually based on more acidic components. Hard water General Hydroponics Flora Range was formulated in response to demand from growers in various areas of the United Kingdom such as London, Thames Valley and other arias with very hard water. It was formulated to correct the (pH) of alkaline water and minimize the amounts of Phosphoric Acid that are required to maintain it at correct levels. It also takes account of the other minerals to be found in Hard water use of this product will ensure the best possible results in Hard water areas.

Did you know ~ that instead of buying an expensive R/O filtration systems that you could have simply bought nutrients that was formulated to meet you hard water needs? Expensive filtration system are made for people how are drinking there water, not growing in it (in most cases)!! With the exceptions of very polluted water conditions.
There is one thing you must remember when dealing with indoor grow/rooms. There is no such thing as a "house plant." Plants grown in interior spaces actually come from deferent regions of the world, and must adapt to less than ideal conditions in the home or grow/room. The gardener's challenge is to know the plant's environmental needs and meet them. The interaction of environmental factors and maintenance practices contribute to the health or decline of the plant.
Now let’s discuses (Soft Water). Any water that does not contain large concentrations of the dissolved minerals calcium or magnesium. This will alter both the (pH) and the electrical conductivity.

DID YOU KNOW….. the purer the water, the lower its salinity and the greater its resistance to the flow of electricity? Salinity is related to conductivity?
DID YOU KNOW….. Soft water does not occur naturally. It must be processed.

Soft water quality all depends on how the water was softened. If the softening was accomplished by an ion-exchange method it is a better process. However, if the water was softened using sodium (SALT), you do not want to use it on your plants imo. Unfortunately, most home water softeners use sodium as the softening agent. The sodium water softener replaces the calcium and magnesium (two nutritional components needed by plants) with the sodium which is toxic to plants in large quantities produced and in most cases that I’ve seen almost all growers that use soft water use it a high levels at 100% of there water to mix in with there nutrients, it would be a better idea if you mixed it like half and half, you know like half regular water (hard water) and your filtered water (soft water) that way it you would stand a better chance of balancing it out to more your plants liking. If you use bottled water on your plants, you need to find out if the water has been softened, and if so, what method was used, sodium or ion-exchange.

Now that you have determined what type of water your going to be using to grow in, it is time to order the appropriate nutrients to go with it. Now that you have your nutrients we well discuses what relation this three elements are going to play in the roll of your (pH) problems.

Basic Water Chemistry!!

Basic Water Chemistry!!

What You Need to Know About Water Chemistry, and Why? In Order To Understand The Make Up Of Your Hydroponics System
What is PH?
Put simply pH is a measure of acidity. The pH scale goes from 1.0 which is highly acidic, through to 7.0 which is neutral, up to 14.0 which is highly alkaline, but really what does all that mine?

Water has four measurable properties that are commonly used to characterize its chemistry. They are (pH), buffering capacity, (GH), general hardness, (KH), calcium carbonate, which determines the (dH), degrees of hardness, (KH) and (dH) are counted as one, and (Salinity), the overall density of all of them combined. In addition, there are several nutrients and trace elements. It is a must: therefore that we explore these four properties if we are to ever understand what makes up a successful hydroponics productive system; in our hydroponics systems water/solutions to determine the health or lack thereof. The ultimate determining factor in the success of any hydroponics system must begin with it’s water chemistry, for that is the life force of any hydroponics system. To say that one hydro-system is designed better than the other, is like getting on your bathroom scales, and for me to hand you a feather, that feather is not going to contribute a noticeable deferens compared to the overall volume of the total mass of your body on the scales, and with that being said, any hydroponic system that is not built to build upon it’s self is a lemon!! I believe you know what I am saying, look at it this way; I believe that The hydroponic manufactures, have been manipulating growers from the begging, by designing (lemon) hydro-systems that keep you coming back constantly to buy more and more of there so called super-products!! I am further stating that the store bought or DIY hydro-systems that I see today are built around the same hydro-physics that the big manufactures are using, there is no greater lie than that of a half truth!! Have you ever been to the hospital and see someone with an IV in there arm, and also with a oxygen tub up there nose? They are intervenesly and mechanically supplying this carbon-bio-unit with what it needs to stay alive until it is able to sustain it’s self, all of the hydroponics designs that I see are built around hydro or hospital physics, to keep you or your plants alive until you/they can start over or what we growers call “flushes” or “nutrient change-outs” to restart the life process over again, this type of thinking works great for saving life’s but were not trying to save life, were trying grow life!! And in order to do this we must change our thinking, instead of thinking hydro-hospital-physics, we must think carbon-bio-physics for that is the only way to sustain life on a perpetual level. This is what the Bio-Buckets are all about!! This is a system that is built upon carbon-bio-physics, designed to sustain life and to build upon it’s self, this system is the only one of it’s design that I know of that utilizes all four properties that are the life force of hydroponics. And without further ado let’s get right into it.
pH
pH as we know by now refers to the water being either an acid, base, or alkaline base, with neither (neutral). A pH of 7 is said to be neutral, or another word you might want to know is (equilibrium) that means when there is nothing present or influencing your water to go one way or the other, that’s known as (neutral) or at (equilibrium). A pH of 5.5 is 10 times more acidic than water at a pH of 6.5. Thus, changing the pH by a small amount (suddenly) is more of a chemical change than you might think (and more stressful for your plants!!) than might first appear.
Two aspects of pH are important. First, rapid changes in pH are stressful to plants and should be avoided. Changing the pH by more than .5 units per day is known to stress plants. Thus, you want the pH of your Bio-Systems reservoir to remain constant and stable over the long haul. Second, plants have adapted themselves over time to like a sustain pH rage between (5.5 – 7.0). your job as a grower is to do your best to keep it in-between those numbers for best results.
Most plants can adjust to a pH somewhat outside of their optimal range. If your water's pH is naturally within the range of 6.5 to 7.5, you will be able to grow strain of mj without any problems. If your pH lies within this range, there is probably no need to adjust it upward or downward.
Buffering Capacity (KH, Alkalinity)
Buffering capacity refers to your systems water's ability to keep the pH stable as nutrients or additives are added. pH and buffering capacity are intertwined with one another; if the water has sufficient buffering capacity, the buffering capacity can absorb and neutralize the added acid without significantly changing the pH. Conceptually, a buffer acts somewhat like a large sponge. As more acid is added, the ``sponge'' absorbs the acid without changing the pH much. The ``sponge's'' capacity is limited however; once the buffering capacity is used up in your system water/nutrient, the pH changes more rapidly as acids are added.
Buffering has both positive and negative consequences. On the plus side, the nitrogen cycle produces nitric acid (nitrate). I feel I need interject some here, remember those little things I talk about all the time you know (Beneficial Bacterium) they are responsible for accelerating nitrogen cycle and producing nitric acid that is (nitrate), right about now there’s another one of those little lights going off in a growers mind. Without buffering, your tank's pH would drop over time (a bad thing). With sufficient buffering, the pH stays stable (a good thing), is this all ringing any bell’s or what!! On the negative side, hard tap water often almost always has a large buffering capacity. If the pH of the water is too high for your plants, the buffering capacity makes it difficult to lower the pH to a more appropriate value. Attempts to change the pH of water usually fail because buffering effects are ignored.
The water that I recommend to use the most in the Bio-Bucket System is simply tap-water, most tap-water has a buffering capacity that is due to carbonates and bicarbonates. Thus, the terms ``carbonate hardness'' (KH), ``alkalinity'' and ``buffering capacity'' are used interchangeably. Although technically not the same things. Note: the term ``alkalinity'' should not be confused with the term ``alkaline''. Alkalinity refers to buffering, while alkaline refers to a solution that is a base (i.e., pH > 7).
How much buffering does your Bio-System need? The larger the (KH), the more resistant to pH changes your water will be. A Bio-Systems water (KH) should be high enough to prevent large pH swings in your Bio-System over time. If your (KH) is below roughly 5.0, you should pay special attention to your tank's pH (test daily, until you get a feel for how stable the pH is). This is ESPECIALLY important if you neglect to do frequent partial water changes or go long term use such as in the Bio-Buckets. In particular, the nitrogen cycle creates a tendency for an established systems pH to decrease over time. The exact amount of pH change depends on the quantity and rate of nitrates produced, as well as the (KH). If your pH drops more than roughly two tenths of a point over a day or two, you should consider increasing the (KH) or performing partial water changes more frequently. (KH) doesn't affect the plants directly, so there’s no need in immediate action but I would keep an eye on it.
It Should Be Noted, So Pay Close Attention: BigToke does not recommend any kind of softening water methods, it is not a good idea to even use distilled water in your Bio-System. By definition, distilled water has essentially no (KH). That means that adding even a little bit of acid will change the pH significantly (stressing plants). Because of its instability, distilled (or any essentially other soft-water processing methods) is never used directly. Tap water or other salts must first be added to it in order to increase its (GH) and (KH).

General Hardness (GH)
General hardness (GH) refers to the dissolved concentration of magnesium and calcium ions. When it is said that some plants prefer ``soft'' or ``hard'' water, it is (GH) (not KH) that is being referred to.
It Should Be Note: That (GH), (KH) and (pH) Although as different as they are all three properties are distinct, they all interact with each other to varying degrees, making it difficult to adjust one without impacting the other. That is just one reasons why that BigToke recommends that beginner hydro-newbie’s are advised NOT to tamper with these parameters unless absolutely necessary, or under the direct supervision of a mentor or a very experienced grower who understands the basic properties of water chemistry. As an example, ``hard'' water frequently often comes from limestone aquifers. Limestone contains calcium carbonate, which when dissolved in water increases both the (GH) (from calcium) and (KH) (from carbonate) components. Increasing the (KH) component also usually increases pH as well. Conceptually, the (KH) acts as a ``sponge'' absorbing the acid present in the water, raising the water's (pH).
Water hardness follows the following guidelines. The unit (dH) means ``degree hardness'', while (ppm) means ``parts per million'', which is roughly equivalent to mg/L in water. 1 unit dH equals 17.8 ppm.
General Hardness

0 - 4 dH, 0 - 70 ppm : very soft
4 - 8 dH, 70 - 140 ppm : soft
8 - 12 dH, 140 - 210 ppm : medium hard
12 - 18 dH, 210 - 320 ppm : fairly hard
18 - 30 dH, 320 - 530 ppm : hard
higher : liquid rock (Lake Malawi and Los Angeles, CA)

Salinity
Did you folks know that by measuring the salinity of your hydroponics systems you can get the total amount of dissolved substances. Salinity measurements count both (GH) and (KH) components as well as such other substances as sodium. Salinity is usually expressed in terms of its specific gravity, the ratio of a solution's weight to weight of an equal volume. One component of salinity that neither GH or KH includes is sodium. Is knowing your Bio-Systems water's salinity very important in nutrient management and long term use? Is knowing (pH), (GH) and (KH) suffices important to any hydro-grower? I will discuss this at a latter time but for now I made up something for you, this is a basic 3D representation of what I am trying to say, once you understand the makeup of basic water chemistry you will have a better understanding of what’s happening in your system.



Nutrients and Trace Elements
In addition to (GH), (KH), (pH) and salinity, there are a few other substances you may want to know about. Most tap water contains an assortment of nutrients and trace elements in very low concentrations. The presence (or absence) of trace elements can be important in some situations, specifically:

• nitrates, which are in direct conjunction with the NITROGEN CYCLE
• phosphates, the second most prominent nutrient. Phosphates have been linked to algae growth. If you have persistent algae problems, high phosphates may be a contributing factor, let me say something here, I do not believe that the lucas formula for the Bio-Buckets use it at your own risk. To control algae, only if not using the Bio-Bucket System, frequent partial water changes are often recommended to reduce nutrient levels. If growing in a Bio-Bucket System that I have laid out, there will be no problems for you because the Beneficial Bacterium will control all algae.
  
  
  Altering Your Water's Chemistry
  Hardening Your Water (Raising GH and/or KH)
  The following measurements are approximate; Note that if your water is extremely soft to begin with (1 degree KH or less), you may get a drastic change in pH as the buffer is added.
  To raise both (GH) and (KH) simultaneously, add calcium carbonate (CaCO3). 1/2 teaspoon per 100 liters of water will increase both the (KH) and (GH) by about 1-2 (dH) degrees of hardness.
  Did you know….the (KH) calcium carbonate and the (dH) degrees of hardness thereof, are the determining factors of your waters buffering capability’s, in other words let’s say that your (pH) to high, and you have to add LOT’S of ph-up to get it back to normal, that would tell me that your waters degrees of hardness which is calcium carbonate is very low!! But if you only had to add a little amount of ph-up that would mean that you (KH) plus (dH) are not to bad off……whoops I hear another one of those little bells going off!!!
  To raise the (KH) without raising the (GH), add sodium bicarbonate (NaHCO3), commonly known as baking soda. 1/2 teaspoon per 100 Liters raises the (KH) by about 1 (dH). Sodium bicarbonate drives the pH towards an equilibrium value of 8.2.
  Raising and Lowering pH
  One can raise or lower (pH) by adding chemicals. Because of buffering, however, the process is difficult to get right. Increasing or decreasing the pH (in a stable way) actually involves changing the (KH). The most common approach is to add a buffer whose equilibrium holds the pH at the desired value. This was what I was talking about of the Bio-Buckets earlier when I said: that if a hydro-system that did not build upon it’s self, then it could not sustain life. Did you know….I’ll bet you didn’t know that the Bio-Bucket System is built around these four basic principals and the support thereof, and that is the (GH), (KH), (pH) and (Salinity).
  Note that the exact amount of quantity needed for (pH) up or down depends on the water's buffering capacity. In effect, you add enough acid to use up all the buffering capacity. Once this has been done, decreasing the (pH) is easy. However, it should be noted that the resultant (lower-pH) water has much less (KH) buffering than it did before, making it more susceptible to (pH) swings when (for instance) nitrate levels rise. Warning: It goes without saying that acids are VERY dangerous! Do not use this approach unless you know what you are doing, and you should treat the water BEFORE adding it to your hydro-system, this is just another reason that I recommend tap-water if possible.
  Products such as ``pH-Down'' are often based on a phosphoric acid buffer. Phosphoric acid tends to keep the (pH) at roughly 6.5, depending on how much you use. Unfortunately, use of phosphoric acid has the BIG side effect of raising the phosphate level in your hydro-system, stimulating algae growth. It is difficult to control algae growth in a hydro-system with elevated phosphate levels.
  Did you know…..that one safe way to lower (pH) WITHOUT adjusting (KH) is to bubble CO2 (carbon dioxide) through your hydro-system. The CO2 dissolves in water, and some of it forms carbonic acid. The formation of acid lowers the (pH). Of course, in order for this approach to be practical, a steady source of CO2 bubbles is needed to hold the (pH) in place. As soon as the CO2 is gone, the (pH) bounces back to its previous value. The high cost of a CO2 injection system makes it non practical for hydro use as a (pH) lowering technique. (for inexpensive do-it-yourself alternatives). CO2 injection systems can be found almost every were on the internet because the additional CO2 stimulates plant growth.
  Softening Your Water (lowering GH)
  Soft Water
  "Soft water" is a relative term, but water to be soft must contain low amounts of dissolved calcium and magnesium, which cause water to be hard.
  Milligrams per Liter Grains per Gallon
  -----------------------------------------------------------------
  Soft 0 to 60 mg/l 0 to 3.5 gpg
  Moderate 61 to 120 mg/l 3.5 to 7 gpg
  Hard 121 to 180 mg/l 7 to 10.5 gpg
  Very Hard over 180 mg/l over 10.5 gpg
  Usually the best home water softeners soften water using a technique known as ``ion exchange''. Your may see this as RO/DI That is, they remove calcium and magnesium ions by replacing them with sodium ions. Although this does technically make water softer, and your plants can tell noticeable difference. That is, plants that prefer soft water don't like sodium either.
  Hard water can also be softened by diluting it with distilled water or R/O water. R/O (reverse-osmosis) water is purified water made by a R/O unit. Unfortunately, R/O units are too expensive ($100-$500) for most hobbyists, but distilled water can also be almost purchased at any stores, but for most folks the expense and hassle are not worth it.

It should be noted, that all of the information in this thread is:

1. Statements of facts! They need no explanation, for they are therefore FACTS!!
2. Statements of practice! There are some portions of this thread that I have inserted things that I have found to be note worthy, that mines that you should think long and hard about what I have just said and why I said it.

One mane reason that I close the thread is because we could all debate on how and what is the best way or method for water quality. The aim of THIS thread is to give the on-going/looking folks a more insight on what I have found to be facts and what I have found to be true; the information contained in this thread should be dewily noted that the whole aim of this thread is about water quality pertaining to the Bio-Buckets. It goes without saying that a lot of information found in this thread could be applied to other hydro-systems as well.

Root-to-Root Travel of the Beneficial Bacterium

• Let’s talk for a minuet about the {colonization levels} of Beneficial Bacterium; because both of my Bio-Bucket Systems share the same reservoir, this will speed up the {colonization levels} and give a more equal spared of the Beneficial Bacterium throughout the recirculating systems, as they travel from root to root the: Bacillus Subtilis GB03 is a Beneficial Bacterium with activity against water-borne fungal root pathogens.
  
• Let me share a little something with you, in an effort to see if I could sweeten up my bud’s, I ran an experiment with some sugar, I used icing sugar which dissolves really easy in hot or cold water, which is a good thing! I put 3 ½ cups of white powdered sugar in 205 gallons of water at the last week of harvest…….well to make a long story short, the plants didn’t seem to mind it at first, but the Beneficial Bacterium was overcame!!! Within one week my water was for the first time ever was infected, and the plant stems became week and soft, and the roots began to decay there was to much decomposition going on for the Beneficial Bacterium to keep up with.
  
• In conclusion: let me say just stick with something like PK-13/14 and you’ll be just fine.
  
• In conclusion to the conclusion: I steal have the utmost confidents in the ability of the Beneficial Bacterium to keep my water cline and healthy, to prove this, when it came time for me to clean my system all I did was just fill it up with plain old tap-water with a little H202, let it run for 24 hours, flush and refilled the system with fresh tap-water let it set for two weeks and that’s it, now I know that my pip’s are coated with sugar residue, but I am very confided that what I left behind that the Beneficial Bacterium will clean up for me, thus reducing my startup time, and if it does not, well I’ll post pic’s of that to.

Put back into your plant-production system a set of organisms that will work for you, instead of against you.

• Most people have the attitude that microbes are all harmful, but in fact, most organisms in soil or in solution are beneficial for plant growth. Modern agriculture developed the view that all disease-causing and pest organisms need to be killed, and so the kill-everything-but-the-plant attitude came about. Unaware that healthy soil or solution in fact should contain more beneficial bacterium, and so a program to wipe out life in soil and solution was initiated. But more and more toxic chemicals have had to be used as the diseases and pests develop resistance with the ever-increasing use of killing agents.
  
• Why don’t the beneficial organisms develop resistance to the toxic chemicals being used? Because almost by definition, disease organisms and pests have a boom-and-bust life cycle, so when one pest organism survives the chemical onslaught, hundreds, or thousands, or billions of offspring are produced. Beneficial organisms rarely employ that kind of growth strategy, but instead reproduce only a few times a year, with perhaps only a few offspring produced each time. Thus, when you use toxic chemicals to control diseases, but in fact kill most of the beneficial organisms in the soil or solution, it takes a long time for the beneficials to return. Thus the likelihood that they will develop resistance is significantly less than that for any disease or pest organism.
  
• Modern agriculture has set the stage for non-stop, never-ending reliance on chemicals. That’s great if you want to sell chemicals, not so great if you need to have drinkable water.
  
• Do we have to go this route? What we need in production agriculture is to help the beneficials more than the diseases and pests. We need to tip the balance in favor of the good guys. What conditions favor the good guys? Do we really need to know all the names of all the organisms in soil or solution, or do we just need to know which conditions favor the beneficials and which favor the diseases?
  I’m just basically tinkering around here with these photo’s
  1. Well the first two of photo’s are of a Thermal Gun that I picked up after going to the race track and seeing some of the race car drivers pop the hood and look at the Radiant Temp with one of these thermal gun’s, so I ask what was going on, and he said, temp gauges most often only check the internal temp’s of a motor, but the thermal gun tales me the surface temp’s of ANY THING!!! So I bought one was a tad-bit expensive, like around $85.00, but I thought I would go ahead and buy it because I wanted to fine tune Bio-Buckets.
  2. Well is a picture of how that I caped off the end of my main’s, they are 1” ½ in size and I just glued the cap’s right on the end’s. Later on I plain on putting water gauges at the end of each line.
  3. Well this is pic is just anther shot of some of the high tek equipment that I use in my grow room. haa eakljkjjjhhh
  4. This shot is of the res, and I decided to do something a little different, I bought some of that plastic screening to go over the top of my res, for two resins.
  • To keep bugs and stuff out of my res place.
  • So that I may remove the lid, and let the res air-out more.

A Hydroponic System That Controls “Bacterial Disease?”

• Well, I knew I would have to write this one day. Hydroponics has a flaw, and I am sure that any day now we are going to get one of those light bulb moments that goes "bing" and it will all make sense. As a whole we treat disease as if it is one problem, and there really are a lot of diseases and they really have to be treated differently. Some people can solve their problem for years then something changes and nothing works.
  
• Hydroponics is not set up to develop these Beneficial Bacterium etc. A more fish tank approach to bacteria is a good idea. High oxygen, media for support Beneficial Bacterium growth, (like lava rock or some other porous rock), recirculating systems are the future of hydroponic bacterial disease control. None of these units exist at this time, for the home grower, other than the Bio-Buckets that I know of. Unless you look at commerchal green house units.

The 3 approaches cannot be used together.

1. Sterilisation - Bleach, chlorine, Monochlormine, Hydrogen peroxide, colloidal silver. Kill everything like a hospital approach.
2. Bacteriological - Beneficial microflora added to the nutrients, and oxygenated to over populate the nasties. Management of the microflora is important.
3. Fungicidal - fongarid/ benlate sprayed on the plants, low doses in the nutrients to provide a pharmaceutical approach.

I think that the development of the Bio-Buckets is the ultimate system for recirculation control. And I have chosen number 2 but it isn't a quick fix. It still takes time to build up enough good microflora Beneficial Bacterium. It takes me two weeks complete the cycle.

Bring the Good Guys Back!!!

• So, what to do? How about putting back the beneficial set of organisms that should be present in solution? The organisms that compete with and consume disease-causing organisms. Bring back the ones that cycle nutrients the way they should in healthy conditions.
  
• What about soil less media? We still need the correct organisms, and the right foods to feed those organisms, so the good guys survive and the bad guys can’t get a toehold.
  
• The Recirculating DWC Bio-Bucket System Support Matrix. It should contain only the beneficial bacterium organisms that protect roots, retain nutrients, cycle nutrients into plant-available nutrients, and allow oxygen and water to move into the root zone easily. If now and again a disease or pest organisms attempts to move in, the existing organisms will prevent it from finding food, from finding the root, or otherwise causing trouble.
  
• We also need to prevent the conditions that allow the bad guys to proliferate. High nutrient loads in the water or support matrix, such as nitrate or ammonium, and lack of oxygen all help the disease-causing organisms grow. A number of publications document this, although more work needs to be done to determine the precise conditions in hydroponics that allow the disease-organisms to win in competition with the beneficials. Hint: Give the beneficial bacterium a place to live in your recirculating hydroponics system and leave no dead spots.
  
• Blight, wilt, rot, mildew and other fungal diseases are serious problems in hydroponic systems. We can predict, often to the day, when disease is going to show up. Some consultants can predict exactly what disease and how bad the disease will be, based on their understanding of the conditions in the hydroponic system.
  
• Wouldn’t it be wise to recognize that disease is inevitable when we attempt to keep things sterile? Disease may be inevitable in some amount in any system, but in a biologically healthy system, such as The Recirculating DWC Bio-Bucket System Support Matrix, the disease won’t run through the production cycle practically overnight. It happens in sterile systems constantly, but never in systems with healthy support matrix, functioning, complete food-webs. Diseases are present in biological systems, but only rarely will crop or yield production fail. In instances when disease begins to outstrip the healthy biology, typically a disturbance has occurred which allows the disease to win. Hint: This is one of the resins that I never do rez change-outs or flush my system. And in those instances, the disease should be controlled through the use of a pesticide. Biology killed by the use of the toxic chemical should then be replaced, to return the system to a condition of health. Pesticides and inorganic fertilizers have a place in production agriculture, but they should not be used as preventives.
  
• Plants feed the “good guys” by releasing sugars, proteins and carbohydrates from root and leaf surfaces. More recalcitrant molecules are released by plant surfaces like stems, bark, stamens, pistils. But because pesticide use has been easy and cheap, in the past, biological interactions have been an area where research has been languishing for many decades. But the ever-increasing need for more and more toxic, greater and greater quantities of toxic chemicals in order to maintain hydroponic systems has brought interest back to understanding biological interactions.
  
• Species by species addition of the needed beneficial bacterium in our hydro systems so that the good guys is present on our plant surfaces. But if we have destroyed the life in the water, by using chemical applications, then the good guys need to be brought back.

Plan of Attack!!!

• The how-to is what we want to concentrate on. Each hydroponics system is a bit different, because the differences are the result of site-specific conditions. Most hydroponic systems allow the roots to hang down into a solution while the crowns are held above or nearly above the solution.
  
• Disease organisms contaminate hydroponics systems through a variety of ways. Nutrients added into the system may contain disease organisms, people moving in or out of the building bring inoculum from other places, insects get into the houses through open doors, through cracks and crevices in the building, and when the plant itself is planted, its surfaces may harbor pathogens, especially the root system. Microorganisms grow in places where the conditions are right for them, but people have a hard time reaching. Cracks in floors, between windowpanes and the window frame, crevices in the hydroponic table itself, stone on the floor of the growth chamber are all great places for disease organisms to get a foothold. Cuttings that aren’t doing well are pulled out and thrown on the floor. That’s food for the disease organism – especially if those diseases were in the flooring material as spores.
  
• The floor is often a perfect place for disease organisms to grow. Nutrient solution drips onto the floor and moves into the cracks and crevices where cleaning solutions don’t reach. Limited oxygen sets the stage for preventing the beneficials from getting a good foothold. Additional food and inoculum comes from diseased cuttings being thrown on the floor. The disease organisms now have a foothold.
  
• Plants need the correct biology in their root systems in order to grow normally. If the normal microflora is not present, then people have to try to perform the jobs of the microorganisms. We can’t communicate with the plant the way beneficial bacterium does, in the root system communication through the language of biochemistry. So we over apply nutrients sometimes, setting the stage for the diseases to win, and then we stress the plants through lack of adequate nutrition at other times, because we can’t talk to the plant to determine minute-by-minute exactly what it needs. Both situations favor the diseases and pests. We need to stop taking the nuke 'em approach and recognize that addition of the beneficial bacterium back into the system is the sane approach.

How To Break the Cycle!!!

• Add the beneficial bacterium organisms into the nutrient solution. Don’t add easy-to-use foods which encourage the bacteria to grow rapidly, so no sugars, no simple protein, no fish emulsion. While beneficial bacterium are needed to immobilize nutrients. The plant produces exudates to grow beneficial bacterium around the root zone, and no further growth substrates are needed.
  
• Plants need aerobic microorganisms around their roots to compete with disease-causing organisms, to help the plant take-up nutrients, and to decompose toxic materials that might harm the roots.
  
• Small amounts of humic acids, fulvic acids, kelp, and possibly small amounts of fish hydrolysate could be added. These foods help the beneficial bacterium to be more active, and keeps bad bacteria from growing rapidly and taking up oxygen too rapidly. Rapidly growing microorganisms use up oxygen, and release carbon dioxide. By monitoring the nutrient solution for oxygen, carbon dioxide, or for microbial activity, you can find out if the solution has been compromised by too much microbial growth before the problem gets too bad.
  
• It is important to prevent anaerobic conditions in the root system, because plants are very sensitive to certain anaerobic metabolites, such as alcohol. Any kind of alcohol. We tend to think about ethanol as being the only kind of alcohol, but there are many, many other kinds of alcohols, any of which can harm plants. The phenols, terpenes, tannins, ketones, aldehydes, and organic acids produced by anaerobic organisms can also harm roots. To say nothing of the loss of N, S, and P in anaerobic conditions. With the use of beneficial bacterium, you can keep these anaerobic conditions from acering.
  
• Can some bad guys grow in aerobic conditions? Only if the beneficial bacterium aren’t active and growing. Hint: If your living space’s are not large enough to sustain a healthy beneficial bacterium colony, most likely they will be over come with a bad case of bad bacteria and lead to rot root if not treated soon, THE NUMBER ONE RESAN for slow beneficial bacterium growth is a lack of oxygen and it slows down the good guys and helps the bad guys have the run of the root system.
  
• Care needs to be taken to make sure the roots are not putting out so much simple food to grow beneficial bacterium and fungi that just that per-unit-of-root food resource results in too rapid microbial growth. Hint: A good balance is needed here, let me explain; for example if your using a five gallon bucket like I do and your using lava rock to give your beneficial bacterium a place to live, as I do. Then you would thank that if you were to put a lot of lava rock in your buckets this is better, I mine don’t we all think along this line? If you have a head ache and the label on the bottle say take two, we’ll take four,dubble what the label say’s! Well to much of a good thing is not good in some cases, and in this case it most certainly is, a good balance is what we need, Mother Nature has found this balance, but in hydroponics we have a ways to go yet. I did careful research and I decided on using the 8” net-pots, because I thought this was a good enough balance, (for a five gallon bucket) and in my initial run of the Bio-Buckets, I grew my plants dabble the size that I normally would, just to see if I could over load the system, but it preformed beyond my expectations.
  
• If that starts happening, what do you do? You add predators to the system to keep the bacteria in control. There are inocula of protozoa available, or you can make your own. It’s simple, effective, and reduces the amount of inorganic nutrient you have to add to the nutrient solution, because the protozoa release plant-available nutrients right in the root zone. In fact, in hydroponic solutions, it is just in the root zone that we see this interaction occurring, not in the rest of the solution.

A Few Considerations.

• So, to start, you have to make good, actively aerated, recirculating designed right bio-buckets. Measure oxygen and make sure it stays in the aerobic range, which is typically above 6 mg/l oxygen. Hint: If you will allow a foot drop back into the reservoir, you will have enough oxygen to sustain over 36 plants, in a twenty five gallon reservoir.
  
• Make sure the balance of beneficial bacterium is present in bio-system before you put your cuttings in it, and have sufficient enough living area to sustain your cuttings.
  
• Having beneficial bacterium is a real benefit in the system, but perhaps not absolutely necessary in high numbers in solution systems. We need to understand these beneficial bacterium better in hydroponic systems.
  
• How much less nitrogen can be added if the organisms are cycling nitrogen? Hint: I use General Hydropoincs Nutrient Solution, and it has been my personal observation, that because of the introduction of beneficial bacterium into your system, you will not need as much nitrogen in your system, so this well be my ratio for my second grow, veg, 0-2-1 and in flowering, 0-2-3, everything looks to be doing very wall at these levels so far. We know that in solid media we have to have 20,000 or more protozoa, typically present as flagellates and amoebae, in order to have enough N release from the bacteria and fungi to maintain plant growth requirements on a daily basis.
  
• So, during the time plants need nutrients to cycle and become available right in the root system, beneficial bacterium needs to have numbers in the 50,000 per ml range. Hint: This is way I let my system set and run for 24/7 for two weeks before I put my cuttings in the system. If we have beneficial bacterium present in our systems when we start our plants, the plant will grow bacterium through production of the plants life, and stimulate growth of the of your plants, causing them to increase in size rapidly. By the time the plant needs nutrient availability maximized, the beneficial bacterium numbers will be high. The beneficial bacterium will be producing maximum amounts of available nutrients, and extra nitrate produced will be taken up by the beneficial bacterium and kept in the system, preferably right in the root zone.
  
• As the plant no longer needs that much nutrient to be made available, as it has stored most of the nutrients it needs for seed and fruit production, it stops releasing as many exudates, and the nutrient cycling system begins to slow down in the root zone.
  
• So, in each root system, each plant requires perhaps 2 to 6 ug of nitrogen (as nitrate or ammonium) to be produced each day during rapid growth. So, you need 50,000 beneficial bacterium per ml to cycle that much nutrient. Later, when the plant doesn’t need as much nutrient availability (assuming you’ve met its demands previously), you’ll be OK with 20,000 beneficial bacterium.
  
• As long as you don’t allow conditions to kill beneficial bacterium, they well remain alive and performing their function.

Nutrient Solution Management and Longevity
for small recycling systems

Due to the many concerns about the non changing reservoir of the bio-bucket system, I have tried to piece together a little something of the workings of my bio-system

There are many ways in which people determine the longevity, or useful life, of their hydroponic nutrient solutions. These range from the "replace it every week or two to be safe" method, to not replacing it at all except between crops. The latter, meant primarily for Recirculating DWC Bio-Bucket System of operations. For the home grower who hasn't the resources nor the financial incentive to have lab tests performed, other management methods are used. As home growers not using lab tests, in this article we will not consider maintaining the elemental makeup of the solution. Attempting to do so without such tests would have no basis in fact and would be based solely on guesswork.

Useful Life
Useful life can mean many things to many people depending on their definition of useful. Two factors can be used to define useful where it relates to nutrient solutions; plant health and economics.

Plant Health

• A solution is no longer useful when it has potential to negatively impact growth or the health of plants, and ultimately yield. The nutritive quality of a solution is determined by the grower at the time he mixes a new solution. I remember a time during the beta testing of my system there was one time that I mess read the ratio for the bloom formula and that caused an excess/build up of salts in the system, even then because of the design of the bio-buckets toxic levels were never reached, if you do get an excess of build up salts in the bio-buckets you better check yourself and see what your doing wrong because most likely you’re the one doing it.
  
• Some have argued that Over time, water and nutrients will be used by plants and will slowly change the elemental composition (or balance) of the original mix, leaving some elements in short supply while others become proportionately over-abundant.
  
  There are two facets involved with elemental availability.
  1. One is the existence of an element,
  2. the other is the effect the chemistry of an imbalanced solution has on the availability of that element.
• An aged solution's imbalance can be such that it either has an insufficient quantity of an element existing in the mix, or that the imbalance has changed other properties of the solution to cause the element to become unavailable to the plants. For example, a solution may have had all but a trace of its nitrogen depleted, or it may still contain adequate nitrogen but it will be unavailable because of the pH shift resulting from the imbalance. Either condition is unfavorable to plant health. The difference being that the former points to a spent solution that has no more useful life and needs to be replaced, and the latter points to a solution which may still be useful but is starting to require more maintenance than desired. Although both points may carry merit, this has been my experience in the bio-bucket system, the reservoir is designed with a float valve, which is constantly adding fresh water back into the bio-system:

• A good day in my bio-system goes like this, you start out with a set point of 1100ppm, and two days later it is at 1050, depending on what stage of growth there at.
  
• It should go without saying that using the plants themselves as a means of measuring the useful life of a solution is counterproductive. The purpose of nutrient solution management is to avoid any unhealthy solution condition, waiting for plants to show signs of nutrient stress defeats that goal. Instead of using the plants as guinea pigs, we use indicators in the solution that will alert us to approaching potential problems so that we can avoid those problems thus insuring uninterrupted plant health for the life of the solution.

Economics
A useful solution will not be discarded before its time. If economy is defined as...... Careful, thrifty management of resources, such as money, materials, or labor, then replacing a solution before it's time is less economical on all three counts. When a solution with a life of 20 days is replaced after 10 days because the stage of growth is now demanding a different NPK formulation, it could be said that was not thrifty management. So in some cases a solution can have too long a life to be economical. On the other hand, when a solution with a life of 10 days is used for a crop requiring only 2 growth stage formula changes, each 30 days apart, it could be said that was not thrifty management of labor resources, because replacing six solutions takes more work than replacing 2. So in other cases a solution can have too brief a life to be economical. The value people place on their time can be much different from that they place on their money or materials. Many would gladly spend a dime to save an hour while others would gladly spend an hour to save a dime. Perhaps the best practice is to seek opportunities to save an hour or a dime whenever the payback can be seen on a repeat basis, where the gains could be enjoyed over and over again. This is what the Bio-Buckets is all about.

Solution Maintenance Required to Insure Plant Health
Although a solution may pose no potential threat to plant health, most growers consider a solution no longer useful when it causes the grower to spend more time maintaining it than is desired. My Bio-Buckets are outfitted with a float valve, which continuously supply’s the system with fresh water, (tap-water, from cold line) not solution. As the fresh water dilutes the solution in the system the ppm’s go down, and about every other day (depends on stage of growth) just add your nutrients at the desired ratio to bring the ppm’s back up to the desired level, as you (add back) the fresh nutrients to the diluted mix which is already in your system, all you are doing is simply refreshing freshly diluted mix, and bringing that diluted mix back to it’s desired level of ppm’s. Needless to say, what is and what isn't a desired amount of time can produce a hundred different answers from a hundred different growers, but it can be assumed that less time is more desirable than more time when results are the same. Solution maintenance can be said to consist of two activities; maintaining the solution volume and maintaining its pH/TDS.

1. Maintaining the solution volume is a matter of adding plain water to the reservoir as its level drops, generally replenishing the reservoir level to its full line. Add backs (another term for water volume adjustments). When it comes to add-backs, it has been my personal experience in the Recirculating bio-buckets that it is easier to maintain a more well balance mix when your add-backs are just plain-tap-water, and not a already nutrient solution mix, if your not going to use a float valve then predetermined intervals usually complimenting a growers schedule, or randomly at the grower's convenience. In most cases, in stead of manually performing and scheduling any repeated add backs, most grower may instead opt to maintain a float valve connected to a secondary water source such as tapped water line, or another reservoir filled with tap-water, to keep levels constant, and maintain that device only once each time a new solution is mixed and water replaced. Water volume adjustments are easily predicted after only one or two crops, if one keeps track of water use during those crops.
   
2. Because of the plants' relatively higher absorption of water than of salts in the water, maintaining the solution volume is essential in a recycling system in order to prevent salts from over-accumulating in the solution. Since add backs are an unavoidable fact of life, and because any additional pH/TDS maintenance and adjustments are avoidable, a maintenance program that limits itself to only add backs will be easier, less time consuming to maintain, and less of a drain on your resources. Furthermore, in the interest of economy, pH/TDS measurements can be performed at the time add backs are made while access to the reservoir solution is already convenient.

pH
One of the most common reasons people replace their nutrient solution is because controlling its pH to stay within its range keeps them running in circles. As a solution ages and nutrients are removed, the ability for the solution to buffer against future pH shifts becomes less. Hint: As a rule of thumb, when running in a bio-system, it has been my experience that the closer you become to that 100% add-back mark that the ph will also begin to lean towards the ph of the original water source, here is were you need to have a maintains plain to do one of two things:

• Flush the entire system, and replace with fresh solution. This will not be a problem if outfitted with drain valves. A fresh solution has a pH behavior that's generally predictable, it will fluctuate but will do so within the acceptable range, thus requiring no adjustments or maintenance other than add backs. An older solution finds the pH wanting to run out of range (usually in the direction of the source water pH), this runaway pH drift constantly needs attention. At this point pH can start to become more trouble to maintain than the trouble it takes to replace the solution and return to the lower maintenance of a balanced and well buffered fresh solution. The problem here is that by the time a grower realizes he's been going in circles chasing a pH ghost, the solution can have already passed its useful life in other respects.
  
• Or, have a plain ready that would replenishes the aged solution? Or not, I have found that it pays to use mathematics rather than guess work when it comes to the useful life of your solution.

TDS
Using TDS as a yardstick by which to gauge a solutions' useful life can be tricky. That TDS drops 25%, or 250ppm, isn't of itself an indicator for possible nutrient deficiencies, or that plant yields will suffer because of it. The assumption often made here is that the starting solution was at or near the nominal threshold of the plants' ability to sustain healthy growth, thus concluding the reduced TDS to be well below the threshold, and possibly deficient in one or more elements. Since it's relative to the starting TDS of a solution, if the starting solution was originally mixed 25% stronger than the nominal threshold, then when the solution TDS had dropped 25% it would be at the threshold instead of below it. Plant nutrient requirements are not something that can be nailed down to the ppm, for that reason thresholds for many crops are given as a range of recommended minimum and maximum elemental ppm values (not to be confused with TDS ppm values). For example, a flowering recommendation might be given as N 40-100 ppm, P 70-100, K 100-200, Mg 30-60. To know your crop's limits is to be able to use it to your advantage. As you can see from the above example, a grower has a good deal of latitude in how he can configure his nutrient solution mix. A safety margin for TDS measurements can be built-in to the original mix by mixing the solution nearer to the high end of a crops' recommended range, doing so will also provide more buffering power thus extending the solution's life to a degree where it relates to pH stability. In other words, TDS can have an affect on pH changes, but pH has no effect on TDS changes, so TDS also plays a role in controlling pH.
Water Uptake
A common rule-of-thumb estimate of water usage in a greenhouse is about 1 liter/sq ft/day for vine crops such as tomatoes. It has been my experience in my bio-bucket system, that in-between maximum/minimum of water/solution uptake, (this is not a static time frame,) for a mature indoor garden under strong artificial HID lighting is about (1qt, US Gallons) per plant.

Water uptake based management determines the useful life to end at a point where the original volume has been completely replaced by plain water add backs. For example, in my bio-bucket system, which has a total of 205 gallons of water in it, when the 205 gallons has had 205 gallons of water added back to it. This is sometimes also referred to as the 100% add back point. As you add back plain water, simply make note of the quantity and replace the solution when the total quantity of all add backs equals to the total capacity. For example, I have a 205 gallon bio-bucket system, 36 buckets/plants are using per plant or bucket 1 quart per day, that’s 36 quarts per day and that equals out to 9 gallons a day.
Tow ways that I have grown in the Bio-Buckets

1. To do a grow without a reservoir change-out, requires mathematical skills and a great deal of knowledge of hydroponics solutions, but can be done if you calculate your reservoir correctly.
   
2. This other way will probably render a more piece of mind for the beginner in the bio-buckets, water uptake based management determines the useful life to end at a point where the original volume has been completely replaced by plain water add backs. For example, when a 25 gallon reservoir has had 25 gallons of water added back to it. This is sometimes also referred to as the 100% add back point. As you add back plain water, simply make note of the quantity and replace the solution when the total quantity of all add backs equals the reservoir capacity. It should go without saying that I have tried both of these methods and there are very little deferent’s between them.

In case you haven't noticed, the determining factors behind a reservoir's useful life can all be traced back to the rate of water uptake, which is directly tied to the current demands of the crop. These demands will constantly increase as plants slowly fill their allotted space, often taking sixty or more days and spanning multiple growth stages before peak water uptake is eventually seen by the reservoir for the first time. As more water is being used by the plants, more nutrients are being removed from the nutrient solution, this naturally affects the nutrient balance in the remaining solution. In essence, the nutrient balance is also being controlled by the rate of water uptake. Simply put, a fuller garden space uses more nutrients because it uses more water. So what we have here is a direct relationship between solution volume maintenance (add backs) and pH/TDS maintenance. When that relationship is recognized, and this strategy enhanced to take advantage of it, additional gains in labor can be realized.
Reservoir Sizing, to buffer ph and nutrient uptake
An indoor home grower wanting a starting point for determining his reservoir size to go the entire grow start/finish, I have used this method with great success, here’s how I did it by approximately calculated 3 US Quart(s) or (2.839 liters) of reservoir water volume for each square foot of mature crop/bud canopy space. This is not to say, the entire veg canopy space of your grow, only crop/bud space!! This is how I calculate my overall canopy space, with each Bio-Bucket calculate one square foot, so you would go the weith plus linth of you grow buckets, which in my case each Bio-System is two buckets wide by eithteen buckets long that comes out to be 18sq feet times two is 36sq feet, this is a rule-of-thumb what I am about to say next, I calculate 3 US Quarts per-square foot and that comes to 108 quarts now dived that total number by four and you should get 27gl and that should be the size of your reservoir. So my reservoir size is 27 gallons, this gives each sq-foot of mature canopy crop/bud space, three quarts per sq-foot. This water volume to space ratio has been found to produce both low maintenance and solution life expectancies that can easily coincide with growth stage nutrient formula changes. Waste not, want not

Management Strategies
Time Based---Management Strategy
The "replace it every week or two" idea is usually safe regarding plant health, however, it doesn't distinguish between those using small reservoirs with large crops and those using large reservoirs with small crops. What really determines solution life is the plants' ability to transpire, which is a function of its leaves. This means that if you have one more leaf today than you did yesterday, that today you would need a little more water than you did yesterday because of the new growth that was born since yesterday. As you can see, water uptake is a constantly moving target, and while it does have an element of time associated with it, it's really controlled by the mass of leaves in a garden at any given time.

To adopt a static time frame for when solutions should be replaced, doesn't account for the scant water uptake from the few leaves found on small seedlings/clones at the start of a crop, compared to the demanding water uptake of what those seedlings/clones will become after 60 days once they possess the thousands of leaves typical of some matured crops. Nor does it account for those gardens using a reservoir size that is undersized for the amount of growth it supports, while other gardens might be using oversized reservoirs. Someone using the "replace it every week or two" method with an undersized reservoir might be safe when a crop is new but not be as safe as he thought after the crop has matured, while someone using an oversized reservoir may be needlessly performing six or more solution changes over a twelve week crop when he could get the same results doing only three changes.

Clearly, time alone and your nutrient solutions useful life doesn't answer all the variables taking place between different grows or the growth stages those grows are in at any given time. In other words, this method is tied to the calendar, not to the plants. I suppose it should be mentioned that I have seen some fertilizer labels suggesting very strong mixes to be replaced at unusually frequent intervals for the strength of the mix. While it's unlikely that crop damage would result from following such instructions, one can only wonder if such labeling suggestions are an honest effort to simplify use of the product or to bolster sales for it, or both.
Enhanced Water Uptake Based Management
Formulating the starting solution mix in concert with the unique properties of your source water can allow you to run a nutrient solution without making any secondary pH/TDS correction adjustments during the entire life of that solution, thus limiting your maintenance to only the unavoidable plain water add backs. For example, an alkaline source water will tend to produce an alkaline solution as more and more of it is added back to the reservoir over time. You can avoid correcting unacceptably high pH levels later during a solutions' life by adjusting its starting pH a bit lower to compensate. Similarly, to keep the ending TDS of a solution from falling below the nominal threshold for a given crop, you can adjust the starting TDS a bit higher to compensate. The advantages of making all corrections at one sitting are obvious, and speaks strongly to the growers' economy of labor. It's not all that different from making the kids pee before they get in the car for that long drive!