Sorry for the terrible picture, I had to take it through the glass at an angle. These little white lumps have shown up in various spots in my tank, rocks, glass, lumps of epoxy. Never on side glass, only on the back. They're not spirobirids, they're larger, maybe 3-5mm. Smooth, rounded, and have a definite dimensional form. Basically little white lumps. I can't say whether they're motile, but they show up in groups. They don't seem to bother anything, but I'm curious as to what they are.



