Now - I never changed out the res solutions. Started low PPM and kept it low. Used AN Sensi Grow & Bloom series nutes with B-52, VooDoo Juice and FF Beastie Bloomz + Bud Candy. Blast away at the nutrients but look at the roots, smell this bud and I'll post trimmed pics and weights when done. Hard to argue with good results. Could they be better? damn I hope so. I don't know squat about hydro except what I read here. This is my first complete DWC and first auto. The res solution is clear as hell, no slime on the roots and never had any. Added touches, and I mean touches, of hydrogen peroxide 2 times just to be safe. Used plain chlorinated tap water pH adjusted to 5.5, seedling rooted in rockwool in RO water. Started slowly adding AN Sensi Grow until she responded at at about 245 PPM and my tap water is 80 PPM so it didn't take much in nutes. I didn't keep records for those anal retentive sorts.
In short I would say if I can take some decent instruments, good nutes, a home made DWC ($30) and never change solutions (just slowly switched to adding the Part B of the Sensi Bloom instead of Part B of the Sensi Grow then anybody could.
Then a little Beastie Bloomz (1/4 teaspoon 3 times) and Bud Candy. Also used the AN VooDoo Juice and B-52 during veg and flower per AN directions (doesn't take much at all and I have enough left for many more grows) and she kept growing. Final height was almost 47" and she was 54" wide mostly due to buds pulling branches out more.