PH before or after adding nutrients?

[Guest]

I've read conflicting information to where some say to PH before and some say after. What is the deal here? PH'ing before might require some people to actually use PH up if after adding your nutrients you get in the 4's. I usually PH'd after mixing. I'm in a coir/perlite mix in a passive hydro setup. I blended 1 part tap water (very hard water) to 4 parts R/O. PH adjusted and bubbled for an hour, bringing it to 6.0. I then added 12ml PBP which brought it in the low 4's. I then added 12ml Maxicrop and tha actually brought it back up to 5.88, which is where it held steady after bubbling in the gallon jug.

So, why do we see conflicting info on when to PH your water? Also, will I be okay with Mg/Ca by using 25% hard water to 75% R/O until I can get my hands on some micro supplements? I understand that without seeing a water analysis it's hard to guess... By the way, what micros does Maxicrop have?

 

[bartender187]

Maxicrop Seaweed has a bunch of micro nutrients... also... i know hard water has a decent amount of MG/CA... ide just experiment with ratios (start low... if you see signs of MG defficency, pick up a CAL-MAG bottle, or add more Tap Water...)

peace

 

[3legdog]

I am not sure what you mean conflict . My thoughts are you just need to have it proper when it hits the plants. You can start by ph ing it if lets say your going to use a certain type of nutr. thats going to have drastic changes but my theory has always been do as little phing as possible & use other nuts...like you have ...to do the so called adjusting for you. My Guano teas sometimes climb too high(7.0) after sitting & or bubbling & i have been using a little PBP flow. to bring it down to around 6.0 or i use a little EJ catalyst to lower it. When i do have to adjust i use the EJ all natural ph adjuster very easy powder/crystals

Best of luck & have a nice weekend all Peace 3ld

 

[Guest]

Well, maybe it depends on what nutrient I guess. I read on bottles that said PH adjust you water BEFORE (caps and bold) adding solution. And then on others, it says AFTER. So that led me to ask the question here.

Btw, I had been using PBP with straight R/O and I never saw the ** Cal-Mag note at the bottom because I'm not sure that was even printed on the bottle when I first bought this product (but I didn't have a R/O at that time so it's possible I just ignored it). Since my recent addition of the R/O filter I've started seeing some Mg-. I'm looking into the other Botanicare supplements.

 

[3legdog]

Right on PG Botanicare has darn near everything now....even a few new ones recently...best of luck 3ld

 

[shaolin730]

I don't grow hydro but my tap water has a pH of 8+ (my tester doesn't go above 8). I use FoxFarm nutes and always adjust after adding the nutes. I don't see a point in adjusting before unless you know EXACTLY what your nutes bring it to.

bartender187, check the DeepChunk thread in flower pics...dude's got another Immortal Technique quote for ya . A couple more Tech fans join the band wagon

 

[Guest]

http://www.wormsway.com/articles/08_03_phandnutrients.asp

Before You Mix . . .

Finally, to prevent possible problems, take a pH reading of the water you will be using and adjust it as needed before mixing your nutrient solution, and never use hot water when mixing hydroponics nutrient. (The ‘scale’ that you see on the inside of hot water pipes is a form of calcium that will raise your pH to irritating levels which cannot easily be reduced.)

http://www.eurohydro.com/anglais/whatsin.htm

Nonetheless, high pH can damage plants in many other ways. So the best way to deal with pH adjustment is to adjust your water's pH, mix in the nutrients, let it stand for a while to stabilize, then test and adjust the pH again.

Why adjust the pH before and after? Adding the nutrients in a well-adjusted pH will allow the very precious chelates not to break down. And adjusting after again, when needed, allows you to make sure your roots will bathe in the most harmonious and complete nutrient solution, an environment where you know they will thrive.

http://futuregarden.com/nutrition/nutrition_overview.html

But before you mix up your first batch, you'll want to adjust the pH of your water BEFORE you add the nutrients so they will be optimally available to your crop. For more information, please see our pH and PPM page.

http://cannabisculture.com/articles/4044.html

There's always been a big debate over when to adjust your pH – before and after you add nutrients to the water, or just after. We talked to an expert, and she said to do both. The reasoning for doing both is that water is rarely dead-on neutral. It's either acidic or alkaline, depending on your region. Our chemist said that the way the professionals do it is to render the water neutral first (pH of 7.0). You would then add your nutrients to that chemically neutral solution and adjust to the desired range within 5.2 to 5.9 pH. Makes sense to me.

 

[Dr Watt]

Yeh, during bloom in Hydro w/ RockWool I think one very seldom needs pH up. Even if the tank pH goes down to 4 (EDIT pH5 - NEVER EXPOSE ROCKWOOL TO SUB 5pH) I leave it because after re-circulation it will be 4.5 XXX. With some photosynthesis it is at 5.2 within a day maximum. Most rockwool will increase medium pH by 1/2 thus after 24 hr the block pH is 5.7.

During Grow/Generation and the tank adjusts even quicker - and it will be go from 4 XXX to 6 in 48 hours. Young plants get a bit poisoned by pH down and I reckon young seedlings prefer growing with less down even if it means growing at a ph of 7 EDIT DON"T KNOW HOW I CONCLUDED THIS - i stick to pH 5.2 or more and outflow from rockwool is then pH 6.

One certain rule for pH up/down is to dilute it before adding. I tend to add after re-circulation and in Bloom allow my ph to range from 4 (occasionally) to 6. It sits at 5.5-5.7 most of the time.

OH YEH - I pH DOWN TO 5.8>6 BEFORE FOOD - my theory is that the pH down can work/expend/interact with the water and contaminants and not interact with the food.

 

[sunnyside]

personal grower...as you have found, if you ask 10 growers the same question, you are likely to get 10 different answers.
Heres the way I look at it... most hydroponic nutrients available today are ph buffered. So You would definately want to mix the nutrients first...let the buffers do their job, and then adjust further.

Have you ever noticed that your ph tends to rise over time in your resevoir...that is because the nutrients are being taken out of the solution by the plants...less nutrient in the solution = less capability to buffer ph = a rise in ph.

What I usually do is mix nutrients to the strength I want them at...then I let them sit for a couple of hours to 'adjust'...my ph tends to stabalize within a couple of hours...then I drop the ph to 5.5 or wherever I want it.
Hope this helps.

 

[Guest]

sunnyside - pH buffered in the sense that when mixed in most normal water supplies it will give a pH between 5.5 - 6.5 (as defined by advanced nutrients). The keyword, and without definition, here is 'normal water'. Which is why some people need to adjust to a normal range BEFORE. It is my theory that if this isn't done first then when the nutrients are leeched from the water then there will be wilder swings in PH, jmho. Therefore, ones needing to adjust before depends on the quality of their water to start with. Perhaps that's the safest answer My R/O comes out about 6.75. When I mixed 3/4 R/O with 1/4 tap the resulting PH after 24 hours was 8.3, if that tells you anything about my tap I have a ph/ec/tds pen coming in monday so I'll be able to at least see my starting PPMs. I'm guessing >= 200 on the tap side.


With respect to resevoir fluctuations, yes, I've been there and done that. Which is why I'm now on to passive hydroponics to where this will not be a problem.

 

[Guest]

Browsing some of my bookmarks I stumbled upon something I must have meant to read at one point (from CW)

pH Changes During the Making up of a Nutrient Solution
When making up a nutrient solution, it is important to adjust the pH of the water before adding the nutrient. The nutrients will affect the pH, and it usually takes about 2 hours after adding the nutrients for the pH to stabilise, as all the buffers in the water have to come to chemical equilibrium. Having a bubbling stone in the solution mixes up the water and speeds this up. I found that if the pH rises somewhere above pH 7.5, then a white precipitate forms as calcium and possibly micronutrients lock up and precipitate out.

I used to always add 18 mL acid and the nutrient, and then add 5 mL of acid 45 minutes later, this gave me a pH of 5.8. But I was very surprised to find that when I added 23 mL of acid and the nutrient all at once to the tank it gave me a pH of 4. So I found that if all the acid is added at once, then this completely over-acidifies the nutrient solution, and the reason for this is the buffering action of the bicarbonates in the water breaks if the solution drops below pH 5.3

 

[Guest]

Good stuff guys... Learned alot.. Keep the great info coming.. peace..

Sack's First Outdoor Grow
LQQK see... Now in 12/12
Sack's Bubbledust Outdoor Grow
Sack's Cappuccino OD Grow
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sack :friends: :joint

 

[3legdog]

Excellent points/quotes

Excellent points/quotes

You did a very nice job researching & posting those quotes for us PG ! I think for the most part we are all on the same page :friends: ...i like what you said that whether to ph before adding the nuts. depends on the quality of your starting water...so true i missed that in my thoughts above. I have been using distilled & rain lately that thankfully are very close to nuetral(7) & both have no ppms of disolved solids...gota love my mtn. rain . Again nice thread very informative.. take care PG & Peace out 3ld

btw what kind of combo meter did ya get ? I have a sharp(milwalkee) tds pen...waterproof & it works great..those all in one meters are very nice & certainly a great addition to any program. Also if your water is 200tds or less out of the tap it's probably not too bad. Mine is over 300 tds & is not usable alone

 

[Guest]

3legdog: A slightly used Hannah HI98130 from a lab. Got it for 45$ so I'm hoping it all works out for me. If I would have plunked down the money in the beginning for a decent meter ,this wouldn't be my 3rd ph pen. Some lessons are learned the hard way I'm hoping it still works out with using PBP because I've read the age-old debate on how it's registering PPMs in a hydro-organic solution.

I've been wanting to get a rainbarrel for a while, or a koi pond with a self-sustaining ecosystem that has most of your nutes built right in. Just a dream though

 

[Guest]

Alot depends on your nutes... water condition to start... and the medium you use.

Why do we see conflicting info? We all have different growing styles.

I use PBP in hydro with RO water. This combination always needs PH up to bring it to the level I want and found to be best for my medium (coco coir/perlite).

Tap water PH 7.5 and TDS is 700 ppm. The RO brings that to 6.2 with TDS of 10 - 20.

When adding PBP the resevoir will drop to 5.0 or so... I like to run my medium around 6.1 - 6.5. I always need to use PH up and the tendency is for it to drift down.

I also use Cal-Mag and Liquid Karma... both will drop your PH... also use a shot or two of Silca Blast and Hydroplex as a bloom enhancer.

Just sharing my experience... your mileage may vary. It's a good idea to get your system dialed in and in balance. It's a good thing to closely monitor you PH and TDS... things can take a dump pretty fast sometimes.

Good growing... Mais-

 

[Guest]

Just some more info regarding buffering. This leads me to believe that mucking with PH after adding your buffered nutrient(s) is working against the buffers themselves. Therefore, working out your source water to have a PH/PPM just about right for the dosage of nutrient to get you close to your base... Just thinking outloud.

Buffering
The buffering capacity, or ability to resist change in pH, is greatest within one pH unit of the pKa for the acid. A complex equilibrium exists between the concentrations of all of the species present in the nutrient solution and the concentration of available hydrogen ions, making the nutrient solution a buffer over a very large range. This is why adding acid to pure water decreases the pH much faster than adding acid to the mixed nutrient solution.

Any species added to solution that can be either a proton donor (acid), or a proton acceptor (base), sets up a buffer.

But on the other hand:

djusting pH The addition of acids or alkalis to nutrient solutions is the most common and practical means to adjust pH, and can be easily automated. There are ways to minimise pH variations and they are worth some consideration. Nitrogen is the essential inorganic nutrient required in the largest quantity by plants. Most plants are able to absorb either nitrate (NO3-) or ammonium (NH4+) or both. NH4+ as the sole source of nitrogen or in excess is deleterious to the growth of many plant species. Some plants yield better when supplied with a mixture of NH4+ (ammonium) and NO3- (nitrate) compared to NO3- alone. A combination of NH4+ and NO3- can be used to buffer against changes in pH. Plants grown in nutrient solution containing only NO3- as the sole nitrogen source tend to increase solution pH, hence the need to add acid. But when approximately 10%-20% of the total nitrogen is supplied as NH4+, the nutrient solution pH is stabilised at pH 5.5. NH4+ concentration needs to be monitored as it has been shown recently that micro-organisms growing on plant root surfaces can convert the NH4+ to NO3-. Since hand-held ion-selective electrodes for measuring both NH4+ and NO3- are now available, it should be possible to accurately monitor and maintain a predetermined NO3-/NH4+ ratio throughout the life of the crop. Phosphorus is required in large amounts by plants. Interestingly, there are two forms of fertilisers containing both K and P - KH2PO4 mono-potassium phosphate (MKP) and K2HPO4 di-potassium phosphate. Equal quantities of both can be used to maintain the pH at 7.0. Using a higher proportion of K2HPO4 increases pH. MKP can be used to lower the solution pH. Buffers are solutions which resist pH change and are used to calibrate pH electrodes. Buffers can be added to nutrient solutions in an attempt to maintain pH stability. One such buffer is called 2-(N-morpholino) ethanesulfonic acid - abbreviated to MES. Many of the companies who claim better pH control with their 'specially' formulated nutrient solutions add MES to their mixes. It is important to remember when using MES, that after MES addition the pH is low and needs to be adjusted to your required level with an alkali such as potassium hydroxide (KOH). Another method of pH stabilisation is to use ion- exchange and chelating resins. Generally, these resins are small beads which have nutrients absorbed or chelated onto them - the nutrient solution circulates through the beads or the beads can be suspended in the nutrient tank. As plants absorb nutrients, more nutrients are released by the resins. The aim is to achieve controlled release of nutrients into the solution in an attempt to mimic the way the soil releases nutrients. Ideally, such release can adequately supply the growing plants' nutritional requirements and maintain pH stability.

 

[Guest]

Right on PG Botanicare has darn near everything now....even a few new ones recently...best of luck 3ld

Locked and loaded. Just got the Karma, CalMag, SilicaBlast, Sweet, Clearex and Hydroguard (prolly didn't need that one). Might as well be wearing a Botanicare T-Shirt

 

[3legdog]

Good stuff PG glad you were able to get so many things in 1 run & yea sign me up for the Botanicare T also :wink: . Have a great weekend playn' the "mad scientist" w/ the new goodies. Peace 3ld

 

[Harry Gypsna]

I think with all the different answers, we still have a consensus(if thats possible lol) and that is to do it whichever way works for you

 

[3legdog]

^^ well said HG