are there ph down products that work better than others? im currently using GH ph down but anytime I drop the ph of my drain to waste reservoir it will slowly clime back up. I'm currently using RO but I'd like to get off of it and goto just filtered tap water. its about 7.8 starting PH so it needs alot of adjustment. is there possibly a nutrient lineup that drops the ph enough that would remain stable because ph down only seems to work for a day or so.