Is this Copepods? or nudibranch?

[RayL]

I just noticed that my 15g currently coral-only tank with a blue hermit have quite a fair bit of floating white things in the tank.

Most are tiny but some are slightly bigger and crawling on the tank walls. Do refer to the attached pic. I managed to zoom in.

a bit of my tank info:

2mths old

tank crashed and only survivors are the bubble coral and the blue hermit.

Therefore converted to coral-only tank

[Martian]

Looks like copepods to me...

[PowderTang]

I also have plenty of that appearing on my nano after 1 month

[RayL]

Thanks Martian!

Was just worried that this may have caused the fishes to die :X

[Powder blue Tang]

I think it's Copepods also, nudi like to lay around buttons corals , if you spot them, nightmare begin

[Ccccz]

look like codepods.