If buying from a hydro store simply tell the clerk what you're using and ask what to add next. I suggest one additive at a time. This way if you get a reaction you don't want you know which additive caused it. May sound strange to the inexperienced. For a current example I have 2 sativa dominant plants side-by-side. I never use full strength nutrients in soil (and these are). Yet one is in the flower room trying to croak from nutrient overdose (and yes it is that despite fractional feedings as I have grown since 1964 and have a couple of clues) while the other is putting so much weight on the colas she is propped up! Same feeding schedule and all. Different strains have slightly different needs and wants.
To DWC. New at this too. Popped a Dinafem White Widow Auto in a rockwool cube and put it in my heater dome. Never grew an auto, never used rockwool, never did DWC or any hydro. It popped in 2 days and in 4 I had to emergency set up a 5 gallon DWCI built. Flying blind now, OK?
I use AN exclusively so I figured I would use that in DWC. I had RO water from our clinic already here. 8 PPM bare, pH 7.1. I adjusted to 5.6, filled the thing and added 1 ML/gallon of Sensi Grow A&B. Barely not water but it was a seedling.
https://www.rollitup.org/auto-flowering-strains/561913-dinafem-white-widow-auto.html
Check it out. If I can do it you can. I raised the PPM gradually - over days, not hours. I added VooDoo Juice next and then B-52. Don't know what to add next and I'm always open for polite suggestions that are anatomically possible.
