I found this in my sorority today . It's close to the filter so I hoping it's just from turbulence. I know girls build nests too but not normally this large. I see no signs of a male in any of the ladies in there but they can surprise you.
Here is a video of them. I'm 99% sure they're all girls but some other opinions would be great. The CT is female for sure, she's my alpha and you can see her eggs. The others are from Darkmoon's spawn and I think they're around 5 months old. Sorry about the camera going in and out of focus and the glare.