I have a fowlr tank 3 months old, 55 gal display, 30 gallon sump/fuge. Parameters are as follows: Amonia 0; Nitrite 0, Nitrate 20; calcium 450. I think I want to add zoas to my tank to add color. I have chosen zoas because I just happen to like them and I can get a rock at lfs with about 30 on...