Majority of reefcentral tanks of the month use reefcrystals. nuff said.
this is hardly enough said....that tells us nothing of their husbandry or setup...that is what makes them TOTM...not the brand salt they use.
And obviously both salts will work fine...they have been used on beautiful reef tanks for many years with great success
I have used both salts for extended periods of time, and would have to choose Red Sea Coral Pro hands down over Reef Crystals. RS mixes way quicker, clearer, and with much better levels. RS uses dehydrated natural Seawater as the base chloride for their salt mix...Instant Ocean uses a bunch of chemicals (and you can tell instantly when you pour out the salt mix....RC will kill you if you inhale that cloud...lol)
But at the end of the day, the tanks I have used RS on have much better color, growth, polyps extension and less algae issues, than ones I have run RC on.
I do like Tropic Marin a lot...I just can not justify the price...when I have gotten better results from RS.
And for the small difference in price between RS and RC...I feel our customers are getting a much better product in the Red Sea....(and there are better margins on the RC than the RS, so I see why vendors would rather sell the Reef Crystals to make more money)
Now on the flip side, the RS can be tough to acquire sometimes....like right now...lol our distributor is out of RS pro...and I had 6 bags and 12 buckets on order to arrive today....and NONE showed up...(this puts us in some serious trouble) but I am pretty sure it is the distributors fault not Red Sea