I had a very bad experience with Red Sea Coral Pro. I was using Tropic Marin Pro Reef and decided to switch to save a little money. I made it a gradual switch but I ended up with a horrible Cyano bloom and my corals started looking very unhappy. I've heard of others having the issue with Cyano before. I don't know what Red Sea does to the salt to clean it after it goes through the evaporation process but my guess is that some of the other things that don't evaporate away like phytoplankton and zooplankton get's into the salt which could cause an algae bloom due to excess organic waste. Again that's just in theory since I don't know what they do to the salt. I switched back to Tropic Marin and my corals slowly recovered and my Cyano bloom went away. I've been using the Tropic Marin brand for years when it comes to salt and I highly recommend it. Very consistent mix, dissolves rapidly, alk, and calcium levels are on point. Magnesium is a little low but not that bad.