I have a Fluval 13.5 that was set up 1/2/2021 and today I cleaned the overflow area for the first time and these critters were all over the place. I did a little research on here and I’m thinking that they are pineapple sponges but a confirmation or any help identifying would be greatly appreciated.
For reference on the size, the large holes in the intank media basket are about 1/2” diameter.
For reference on the size, the large holes in the intank media basket are about 1/2” diameter.