I have a 180 gallon tank. Most of all the coral is SPS. My main issue Iv been having is keeping my Ca. and Alk. were they need to be. One of my friends was going to sell me a 2 stage Calcium reactor. SO my question being would adding a Ca Reactor to my system stop the corals from RTN all the time. I think the alk is swing to much and the Ca is only at 350 could be part of my prob(Mag is at 1375). So if the Ca reactor is a good idea that should maintane the alk and Ca correct? Also what is the best brand of media to put in it? Hopefully someone can help me! Thanks : )