The degradation rate is very slow in ambient temperatures. A 2017 study found that at 25 °C (77 °F) in seawater, PLA showed no loss of mass over a year, but the study did not measure breakdown of the polymer chains or water absorption.[55] As a result, it degrades poorly in landfills and household composts, but is effectively digested in hotter industrial composts, usually degrading best at temperatures of over 60 °C (140 °F).[56]
It is PLA, which is aquarium safe.
From Wikipedia
The degradation rate is very slow in ambient temperatures. A 2017 study found that at 25 °C (77 °F) in seawater, PLA showed no loss of mass over a year, but the study did not measure breakdown of the polymer chains or water absorption.[55] As a result, it degrades poorly in landfills and household composts, but is effectively digested in hotter industrial composts, usually degrading best at temperatures of over 60 °C (140 °F).[56]