I usually start mine with plain tap water for the 1st week or two, Then I run my jacks at .08ish and bump up gradually from there... Here's one about to come out, start to finish with Jack's 321. Simple, cheap, and great results
Last one put out 25 plus zips under 600w cree cobs in half of a 4x8. I had more room on that side so i could have fit some more in, increasing the gpw.
I have 12 of these just for flower. They work great. Got mine from @CobKits also. He can explain the difference from 80 to 90 cri. When in doubt, mix & match !
4x8 , 1side, 1 plant, 600w cree cob, 26.5 oz. I've also had 12 plants with half the yield of the one above. I do 2 in a 4x8 now. Depends on your growing style