Yes, Reef Crystals will dissolve more readily than most other salts. I have tried/mixed all of them. One thing to watch out for is to make the salt dissolve easier, the manufacturer has removed some of the mag. Years ago, I tested the mag in reef crystals and IO and IO mixed at about 900-1000 ppm
and reef crystals mixed at about 800 ppm
I recently have been having issues with IO, got a new bag on Mon. and newly mixed water gave these results...
From talking to others about their salt, I think I've been getting some anomalous readings, but I plan on calling the manufacturer about this and see if they have altered their formula recently (within the last couple of years)