I've used IO: Reef Crystals, Tropic Marin Pro Reef, Oceanic, and I'm trying Coralife right now since I've heard good things about it. So far out of the three I've tried I liked Oceanic overall the best, the calcium levels were the highest out of those three I believe and I didn't have any problems with it. I've only had one water change with Coralife so I can't really judge it yet. I don't really think Tropic Marin Pro Reef is worth the money though so if I were you I'd stick with Reef Crystals, Oceanic, or Coralife.