Hows it going Dutch?

actually I went to a 40 gal Panda for the pipe system, then to 12- 5 gal grow buckets on the 40 gal, then switched to two 20 gal GH tanks each one feeding 6 buckets

In the beginning I tried to stay around 5.2 Ph, but it meant constant adjusting

changing to Latewoods method plus bigger tanks pretty much solved the big dive,now its a slow drift UP

I have been looking at an IntelliDose ph controller by americanhydro

what color are your roots?

100 ppm water should work just fine ,no need for a RO headache, maybe a carbon filter but you will need to measure ppm before and after filtering to see if it changes