A number of things really. Started from alk swing when I added in new sand, then bad bucket of salt.... The bucket had a crack in it when delivered I thought nothing of it so started using it to find out it was all mouldy about half way down basically tank collapsed. Now the rock smells a bit so just trash and start again.
man, i'm really sorry to hear that. Your tank was one of the nicest I've seen.
Preordered mine. Now just biding time until Reefgeek gets it in. I'll post pics of the setup once it's up.