I have a bunch of equipment about 5 years old. Wondering if I can:
1. Reuse bucket of reef salt? I understand the particles can settle. Can this be re-mixed up? It's quite solid salt now.
2. Reuse old test kits? I know they have exp. dates. Does that make them completely unreliable after expiry?
3. Live rock? I assume this is now dead, but can it be repopulated?