I use it on some of my tanks. I just get a "filter bag" and place peat in there and then put it in my canisters. It lowers PH safely IMO and does it over time instead of one big shock (which is what you want, a gradual decrease). I replace mine every few months, because I believe it wears out over time. I got a big bag of it, I think its called Laguna or something, its meant for ponds.