Ok, so good input from everbody thanks. I did my monthly water change last weekend - my tank is at 12dKH (tested earlier today). I know normal is between 7 and 9.. I have VHO super actinics along with 3 250watt 14.5k MH. I have coraline growth on my rocks, it's just never been rampant like it used to be. I don't test Mag yet unfortunately. I don't use any buffer right now.

Sounds like I need to try one of these products!