I use a "Discus Buffer" that I bought from "That Fish Place" pretty cheap. Then I give it a squirt of Tetra Black Water Tonic, but not much. Afterwards you can check the PH and adjust with more if you like. Amounts tend to depend on your water. I also use half and half - - tap and RO water. If you are serious about fish, RO water is a necessity and bare bones units are only 80 or 90 bucks. The Discus Buffer goes down to about 5.8 which I find OK for most of my South Americans and my plants. I must admit that there could be some phosphates in it but I have not had much of an algae problem with it. Anyone not using RO has tons of phosphate anyway. Peat is a messy pain in the bog. Besides, I guess I don't mind a bit of algae. The fish pick at it.