PPM Levels for DWC Plant stage.

Im just wondering what the ppm recommendations are for all the different stages.
I have some seedlings sprouted in rockwool and the roots are just coming out of the pots now and going into the bucket. I currently have a PH of 5.8, and 300 ppm of DNF Grow A&B Mix. Check out my Diary for pics. Also when should I switch from my 2x45 Watt Flouros to my 600 HPS.

StartingOver, I dont have an answer to your question but a question of my own (sorry)
what size net pot is in your gallery pictures, this looks like my set-up will be.
can you tell me a little about your system? it looks like a regular DWC with an airstone.
Thanks!

If the roots are already in the water, you can put them under the 600 now. Keep the 600 3-4 feet above them for the first few days.

Raise the ppm to at least 500, 1 ec, when you put them under the 600. The lighter colored seedling looks like it is already hungry.

When they start to take off, lower the light and up the ppm another couple of hundred ppm.

Nutrient Solution PPM per Stage (Suggested)

Indica's
Seedlings and clones 300-400ppm 5.3-5.5 ph
early vegg 500-600ppm 5.3-5.6 ph
middle vegg 600-800ppm 5.4-5.6 ph
late vegg 800-1000ppm 5.5-5.7 ph
early flower 1000-1300ppm 5.5-5.7 ph
middle flower 1400-1600ppm 5.5-5.8 ph
late flower 1000-1100ppm 5.5-5.7 ph
ripening 300-500ppm 5.4-5.6 ph

sativa's
seedlings and clones 250-350ppm 5.3-5.5 ph
early vegg 300-500ppm 5.3-5.6 ph
middle vegg 500-700ppm 5.4-5.6 ph
late vegg 700-900ppm 5.5-5.7 ph
early flower 1000-1100ppm 5.5-5.7 ph
middle flower 1100-1300ppm 5.5-5.8 ph
late flower 800-1000ppm 5.5-5.7 ph
ripening 300-500ppm 5.4-5.6 ph

Just so you know, there's no such thing as PPM. How high the EC is a question that only the plant can answer. It does no good to measure new nutes until you measure used nutes several times. Feed at 1/2 manufacturers nute recommendation. Record EC over several days. If it goes up, you're too rich. If it goes down, you're too lean.

No such thing as PPM? That is one of the most standard measurements that has ever existed. Although EC and PPM can be different at times, there's always a conversion. It's like saying that there is no such thing as inches just because there's centimeters, lol.
*whap* quit insulting my 150 dollar trimeter! lol, but in all fairness, you need to figure out what people who use DNF nutes run their ppm's at.

Some nutrients have more micronutrients and such than others, so you could be registering 300ppm, but how much of that is nitrogen, and how much is magnesium, or calcium, or iron, or phosphorous, or zinc, etc. So you need to test the boundries of your own nutrients.

Also, that list that basement420 gave is kinda bogus as hell for DWC, first off, with the pH always in the 5's, you'll have poor flower development, and second off, I've rarely had a plant in dwc enjoy a salt bath of 1100-1500ppms even in late flower (although if you are using weak nutrients, it may take 1500ppms, I've never had to go that high using quality nutrients).

my plants burn at around 1200, at the the peak of intake... My goal is to never get below 600, and never above 1150 when I'm in flower... Sometimes I meet that goal, sometimes not, haha... I was using Technaflora's BC line of nutrients in soil, dwc, nft, ebb'n'flood, swc, and aeroponics, but now I'm using GH because it's cheaper and it dissolves nicely for aero.

So experiment... seedlings shouldnt need much nutrient (less than 100ppm) until their 21st day, this is usually when the cotyledons dry up. Then I'd start low, 200-300 ppm, raising 50 a week, if your ppms go down(because your plants are taking nutrients + water), raise it to +100 a week, if the ppms go up (plant is taking in more water than nutrients), lower it 25-50. And let your pH swing from 5.5-6.9, it should happen anyways with a 5 gallon res, but don't be overly cautious about correcting it down so much, it can get as high as 7.2, but higher than that and it will lock out most important nutrients.

Good luck with your first DWC, I think you'll love the results.

-- steve

stevewinthrop - Not trying to give bogus advice but I found that chart on here many months ago and have been using it for my newest grow and I have never found a problem with it. I run GH nutes in the lucas ratio with additional floralicious and koolbloom. And what is wrong with having the PH set in the 5s? According to this the chart below, 5.8 is about the perfect PH for the uptake of the most separate nutrients.



Also I have had my PPMs as high as 1500 recently with no burn or other ill affects. Here is a picture of the plants while at 1500PPM.

Exactally man, what I'm saying is some nutrient brands you can go to 1500, some you can't, some plants can take 1500 of GH lucas, some can't.

Also, with that graph, there's a much better one around, I'll see if I can find it. And as you can see, the flowering nutes are higher pH, and the growth are lower pH. You're saying 5.5-5.8 as flowering is in it's height, that will BARELY reach the threshold at i believe 5.8 for the main flowering nutrient, Phosphorus. You'll be pulling in much more leaf and root nutrient than you will flowering nutrient. I'm sure it will work, but according to your chart, your levels should at least get to 6.5 for maximum phosphorus uptake.

*shrug*

-- steve

If you could find that better chart i would be very interested. I am not trying to start problems here so please dont take my post the wrong way, I am merely trying to find the best answer and posting the answer as I understand.

stevewinthrop said:

No such thing as PPM? That is one of the most standard measurements that has ever existed. Although EC and PPM can be different at times, there's always a conversion. It's like saying that there is no such thing as inches just because there's centimeters, lol.

Click to expand...

Not true, Your comparison doesn't apply. Wherever you go, an inch is an inch, a centimeter is a centimeter and EC is EC. Not so with PPM. PPM changes with the tides. A PPM of 500 is identical to a PPM of 768 while a PPM of 640 and a PPM of 640 are two different things. There are EC meters that display EC and EC meters that hide EC if favor of nonsense. You have one of the later.

Fortunately, plants are illiterate. They don't care if your numbers are nonsense. If your meter tells you which direction the numbers are going, you can run the garden. It's conversation that's impaired.

Define 100º
A) Below freezing
B) Near body temp
C) Boiling
D) Not a temperature at all. Its an angle
E) All of the above

The answer is E

Before PPM means anything in conversation you need a minimum of 5 numbers. Still, PPM 400-512-520-560-614 remains meaningless unless the other guy knows what those numbers mean and which apply to them. EC 0.8 is 0.8. and nothing but 0.8 no matter where you go or who you talk to. It's what your meter measures before it mangles the truth into nonsense.

Holy threadjacking Batman.

Not at all. PPMs on a chart tell us nothing. PPM changes meaning everywhere it goes. The chart has never met the plants in question. Measuring new nutes is a waste of time if you don't know the feeding level your plant needs.

By measuring used nutes we know exactly what solution the plants want. By using EC, we know exactly what is being said.

Well my nutrient meter has 2 digits. and it says next to it on the plastic " PPM x 100, which I would think means to get ppm , times by 100. so right now its at 03, which means 300 ppm. Is this going to work or should I get an EC meter. Caues Im not a big fan of just eyballing the plants for instructions cause I usually end up doing opposite of what I should do, so I rather stick with proven number and measurement formulas.

My nutrient label says use 1/4 strength for Seedlings and cuttings in hydroponics. which ias 1.25 ml per litre. i figure i have 4 gallons water in a bucket. so 1.25 x 16 = 17.5 ml for 1/4 strength. I put in 10 ml, so more or less, half strength of the 1/4 strenght ratio. Which Puts me at 1/8 strength. And that is 300 ppm. It sounds right I guess.

FreezerBoy, I don't completely understand what you are explaining. Are you saying that the only true way to feed my (coco)/ hydro plants correctly is to measure the EC of my nutrient solution and the EC of my run-off/ waste water? Then I would make changes from there?

So I would start at 1/2 manufactures recommendation and use the EC of my run-off water to determine weather my plants are using more water or more nutrients. What would be the difference between me using (seedling) strength nutrients for my seedlings and testing PPM? Have I been looking at this wrong? Bare with me. I might be a slow learner but once I get a grip I never let go.

Hopefully these questions do not read wrong. It seems like a lot of spat's on ICMag begin as misinterpretations of post and that's not what I'm about. I just want to understand your views and learn a thing or two about Herb along the way.

this will help

this will help

here's a couple of feed charts to use as a ref as i really did'nt get to read the thread(kids) it's based on GH 3 part but you can use the ppm's as a ref and the great thing is that it's for the cycle use this for 3 grows and you'll be dialed in as long as you watch and listen to what the plant is telling you that it wants and needs...............Keep it green