Main thing, test your water: eliminates a lot of guessing, which is why answers are all over the map. If you have tests (Salifert is a good brand) for Salinity (tester), Nitrate, Phosphate, Alkalinity, Calcium, and Magnesium, you're pretty well supplied. If you test mg every other week, and alk and cal if mg falls; plus test nitrate and phosphate and salinity monthly, you'll be able to tell WHAT is going on and how to fix it at any given time. Corals are actually easier than fish, but you do have to establish a baseline for your water conditions and then test if you suspect water quality has veered off. Fixing it is usually a matter of putting in a teaspoon or so of the correct supplement powder.
