My palludarium has no fish yet I'm still working on getting the aquatic portion set up so there is a decent amount of organic material in the water but there is a filter and bubbler. I have only added duckweed I bought online and a plant from PetSmart both of which I thoroughly rinsed. I still found these rather large worms in there which I used long tweezers to pull out of the substrate when I saw them against the glass. The 2nd picture shows no worms just the water and substrate, it's night so the tank lights aren't on.
by Difficult_Ad_9359