I am 8 days into setting up a new biocube 32 gallon. Salinity is 1.025, ph 7.8 - my ammonia, nitrite and nitrate levels are all 0 and have been all week long. I have 2 clownfishes and live rock/sand. Why is my ammonia 0, it has not spiked? Salt is Red Sea Coral Pro - I am careful about not overfeeding. Why are my levels 0?