Soil ph 6.4 - 7.0
hydro ph 5.5 - 6.0
I use ph down all the time, i mix up 5 gallons nute mix at a time so it usually takes me 3 caps full to bring it down .5, so put some in then test the water until you reached the ph you want, be careful when i used it on less than a gallon i used a couple...