Hi, I'm new to the saltwater hobby and everything I see that I did not add to the tank freaks me out. I have these small white bugs on my glass I read about them and it sounds to me like some sort of copepod. I fed my tank cyclops at the start when I added my first fish as the banggai cardinal did not eat anything else at the start. I started with dry rock and sand so no hitch hikers, I did the cycle and I see one or 2 of these things at the start didn't bother me so I added a clownfish and a soft finger leather coral all doing well but now these thing are everywhere. I use my algae magnet to get them off but the next day they are all back. They mostly sit on the algae that forms on the glass.(Sorry for the low quality picture)
