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Single best ppm for DWC


Frankensteins Lab Leader
AFN Gladiator
Dec 15, 2013
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I agree on the fact that many people tend to overfeed thinking they can force feed a plant, which you can't, and that leads to toxicity. However, the ideal PPM range is but one factor in having a quality grow. Light, PH, and CO2 levels play a part also. We'll ignore CO2 for the average grower is not supplementing. Light however, makes a difference. The higher the light levels, up to the max a plant can tolerate without added CO2, the more nutrients it can consume. As we all run different lighting and most don't have a quantum light meter, then this is the fudge factor.
That said, 450-525 PPMs will work well for most strains under light intensity of 500-700 PPFD, which I'd say cover a majority of growers.

And there will always be plants that won't cooperate no matter what you do....

My goal in growing has always been: simplicity, consistency, quality. A big harvest is merely a bonus. If your growing for quantity, then you need to use a different set of parameters and need to learn to fine tune the max your strain(s) can handle and determine if this is the point of maximum harvest. The two do not necessarily coincide!

Your opinion is the accepted wisdom, but I wonder whether it's correct.
It's also accepted wisdom to increase feed until leaf tips start showing orange, then back off.
(A minority of growers probably take the opposite approach, and don't increase feed until leaves look too light green.)

Maybe the "wait for yellow" leads to over-feeding, even after the backoff.
And maybe the plants are getting optimal food long before the yellow happens.
If that's true, then maybe a lower ppm could work for all strains at all life stages. That's certainly what happens with wild plants.
I tentatively believe that this "one size fits all" dwc ppm is somewhere between 300 and 450 on the 500 scale.

The fact that so many people have so many plant issues makes me suspect that over-feeding is the rule, and that many people, especially new growers, could benefit from a single, constant ppm.

I have fallen into the over-feeding trap, even very recently.
It's psychologically difficult to resist the temptation to "feed more to get more."


Auto Warrior
Jan 28, 2019
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This is a really good thread I’d really like to run DWC on my autos!