This is a fellow reefer that sent that question to the makers of instant ocean salt
Here is my question and answer from the company that makes Instant Ocean and Reef Crystals.
Sent: Fri 7/30/2010 1:52 PM
To: US Aquatics Consumer Support
Subject: Instant Ocean Salt
My bag of reef crystals has gotten a little clumpy, and there are crystals suspended in the water. Is it still good? Should I wait for the crystals to settle to the bottom before adding the saltwater mix to my tank?
If the salt mix has become clumpy from moisture, it will not dissolve properly. Be sure to test the water to make sure that all levels are still within the proper range. As long as everything test ok it would be fine to use. The suspended particles should not hurt anything, but I would try to avoid getting them in the tank as they probably will not dissolve there either.
125G Reef Tank and Corals
29G Reef Tank and Corals