If you saw 20 then theres probably 20x times that in there. LOL sometimes I have a pod explosion and there are literally thousands on my glass. It dies down after a few days though, the pod population pretty much balances itself out.
180g- Mostly BIG fish and some coral. ~80g Nuvo- My coral tank with "happy fish"~ 90g- FOWLR Not the not happy type of fish~ 125g- Freshwater Malawi Cichlids ~10g- Nuvo- The refugees from the Ich of '18