I can't confidently advise on those products because I have never used them. However, po4 minus, if its similar to gfo, could cause loss of color also. Gfo does it to me. Usually when it's a new media. So I start it slowly and only use a couple days every two weeks until their is some po4 build up. I have a 125 gl that I only use .25 cup on. So I use a tiny amount.