Sand on the side of my tank

[GoLowDrew]

When I clean my tank, I noticed there is "sand" on the glass surface on the side of the tank. I had to scrape it off as I clean it. It feels like speckle of sand. I don't really think it's sand.

Is this coral growing? Calcium?

I've started to add some calcium suppliment here and there, on the light side.

Is this good or bad?

[sir_dudeguy]

look realy really close...if its moving its just pods..to be more presice, probably copepods. Pods are good for an aquarium tho so dont worry bout them.

there are a few bad isopods tho i think...i konw htat one of them has big black eyes, but they dont look anything like the little white specs on the glass.