I recently switched to Reef Crystals for reasons of identifying issues within my tank. It's been approximately six months since I've switched and during that time the problem has persist so it's not the salt. Slowly I'm making subtle changes hoping to catch the culprit. Once I do I will be switching back as I've ran it exclusively prior to this and loved it.
As for the storage, once mixed the general consensus is it must be used within I think 36-48 hours to take full advantage or the "bio-actif" polymer ingredients. Which according to Topic Marin are naturally occurring long chain Marin polymers extracted from sea weeds. Which do act as a carbon source amount other things. Because of which they will start to congeal if you will within the mixing container.
If your in the habit of mixing large quantities for use over time I'd switch to the regular Tropic Marin. Be careful not to get the Pro series. That salt is intentionally low on alk as it was and is designed specifically for long running (years) systems where high alk is the norm.
