My tank is 48 gal, fish only, my base is 100 crushed coral,,. I have 2 striped damsels, 2 blowfish, 1 red legged hermit. I have a charcol fileter and Magnum 350 pump. My tank is 9 mos old, my Ph is 8.0, salinity is 25 ppt, I have never had any nitrites or nitrates register on my tests, same...