if one of your stages is a carbon filter that can take whatever is changing the ph like chloramine or chlorine with ro. i just have a problem with the waste and the fact it takes hours to make a gallon. that and i just cant see not using my tap water if i can get around the ph issue. from what weezard and low-rdr were telling me about vitamin c that sounds like a real good option too. i just dont want whatever is causing my ph to change building up in the soil.