Instant Ocean Reef Crystals crashed my Tank!

[rayjay]

Even if it had been a bad batch, all the forums would be getting complaints by all the people who would have purchased the bad batch. I very much doubt that you would have been the only one getting a bad batch.
Salt mixes are often used as a scapegoat for things that go wrong, when it fact, at worst, it is only a coincidental occurrence.

[Jaysan]

It might have been that you switched salts.
The parameters for Reef Crystals may be different from the parameters of the salinity salt even if you have the salinity at 1.025.

I've read somewhere before that changing salt may not always be a good idea.