Title says it all. I didn't put this in the skimmer and I don't know of anything in the aquarium remotely similar.
The growth in question is in the middle of the picture near the back of the skimmer body. To me it looks like it could have polyps, but I have never seen a polyp on it. The texture kind of looks like soil.
The growth in question is in the middle of the picture near the back of the skimmer body. To me it looks like it could have polyps, but I have never seen a polyp on it. The texture kind of looks like soil.