I have a 75 gallon tank. The hydrometer is reading 1.025, pH is 8.2, ammonia is 0, nitrite is 0, and nitrates are at 20ppm. The tank is just over 2 months old. I have a 400 bio-filter, Aqua Clear 50 powerhead, 70lbs of live rock, 2 false clowns, 1 6-lined wrasse, 2-cardinals, 3 shrip, live...