I used Instant Ocean for a long time just the regular salt not the crystals. I just switched a few weeks ago to Tropic Marine Reef Pro. A little more expensive, but I figured just like anything else in this hobby you get what you pay for. Plus it came HIGHLY reccommended and they have been around just as long as IO (30+ years). So far things look great, after two water changes things have opened up more and look good. The only thing I've noticed is the PH drops the first few days then starts to climb, this might be because something I'm doing. I've been adding B-Ionic the day after because the PH starts to get to low. But when I mix it the PH is dead on, it's all trail and error. But I do not need to dose as much as I did with Instant Ocean ;)