Diagnose slow decline

[reefwars]

- amphipod population slowly declined
- chaeto has slowly died off
- cyano and green hair algae on sandbed
- no algae growth on glass anymore (good for maintenance but doesn't seem healthy)
- 2 snails have died
- protein skimmer pulling out less gunk (also more volatile, harder to adjust)

is it possible your tank is contaminated somehow like the silicone??