Are these eggs? Worms?

[Isozephyr]

I started noticing these a couple months ago, since then I have literally had an explosion. Their are hundreds upon hundreds of these things appearing out of the blue in my sump and overflow box, their are none in the main tank whatsoever. I just do not have a clue what they are, and my main concern is whether this is a good sign or a bad one. They kind of resemblr little maggots but they don't move, they just stick to the glass....a little worried

[MISTERFIXIT]

I've got plenty.


Marc

[greenbean36191]

They're small sponges. They're harmless.