As I've said before in another post I am new to reefs. My corals are doing amazing, they've really blossomed and a couple have doubled in size in just the past month! I've also started to see some new polyps around on some rocks that were coral free when I started the tank. However I don't have the equipment or knowledge to test the calcium and magnesium levels. The LFS kid told me I need to supplement them, but I don't know what to do. What's the best test kit or device? What's the best way to supliment? How often should I test the water?