I have a 236g mixed reef, peaceful. I put a standard cuc of hermits and snails from reefcleaners. These guys were there for well over a year. Over time I built up algae with no idea how it was happening. No changes to feeding or what I dose (minor amounts of ab+ and reef plus trace). When the algae started I stopped dosing, but I noticed the entire cuc had been wiped out. I put in two emerald crabs and they are fine. The only thing I have seen messing with the inverts was the engineer goby. Could he have literally killed them all? I’m guessing by stressing them out when he moved them? I’m struggling to understand why they died, but my cleaner and peppermint shrimp are fine, and as far as I can tell the inverts that stick to the rocks or glass are all alive.