Seems to me they can handle a wide range in DWC.
I burned one of my plants a little while after my first seeds sprouted in Sunshine#4 with some nutes I mixed. Later on I discovered a couple male plants and eliminated them, but I experimented with the clones. I hadn't done any DWC yet but I put one of them in a styrofoam floater over an airstone in the res that burnt the plants so I could watch it die really fast from burning. But what happened? It didn't do anything! It thrived!
So I thought, Hmm.. it's been a while.. maybe these nutes have somehow dropped off in here. I watered the other male clone in the peat pellet with the same res water and it burnt to shit.
Conclusion for me is that in soil or flood-drain or anything where the roots dry out, you need less PPM, as it goes wayyyy up as things dry out. If they stay wet all the time, like DWC. You can pump a lot in there, and it'll just go down as the plants eat it.
My nute formula works out to 1100PPM in veg. And I just give them that right after they root straight through until I switch them to bud. Then it's 1430 until I start jacking up the sugar daddy and awesome blossoms a bit more right near the end. The growth seems to be the same whether there is 1100PPM in the res or only 300PPM left near a change. I think they just take what they need, as long as you're within reason. My observations anyway. I love DWC, so easy.
I burned one of my plants a little while after my first seeds sprouted in Sunshine#4 with some nutes I mixed. Later on I discovered a couple male plants and eliminated them, but I experimented with the clones. I hadn't done any DWC yet but I put one of them in a styrofoam floater over an airstone in the res that burnt the plants so I could watch it die really fast from burning. But what happened? It didn't do anything! It thrived!
So I thought, Hmm.. it's been a while.. maybe these nutes have somehow dropped off in here. I watered the other male clone in the peat pellet with the same res water and it burnt to shit.
Conclusion for me is that in soil or flood-drain or anything where the roots dry out, you need less PPM, as it goes wayyyy up as things dry out. If they stay wet all the time, like DWC. You can pump a lot in there, and it'll just go down as the plants eat it.
My nute formula works out to 1100PPM in veg. And I just give them that right after they root straight through until I switch them to bud. Then it's 1430 until I start jacking up the sugar daddy and awesome blossoms a bit more right near the end. The growth seems to be the same whether there is 1100PPM in the res or only 300PPM left near a change. I think they just take what they need, as long as you're within reason. My observations anyway. I love DWC, so easy.