White Round circular things...

[ubasu]

I have maybe a dozen of these guys pop up under the overflow box. I have never seen guys like these before. Pics below.

Group shot:

Front:

Back:

 

[unchaotic]

Lacking any idea of scale or what's in your tank; the first picture looks like snail eggs to me. I had them all over the place when I had a dozen+ nerite snails.

 

[ubasu]

Lacking any idea of scale or what's in your tank; the first picture looks like snail eggs to me. I had them all over the place when I had a dozen+ nerite snails.

That is the CM side of the ruler. It is a little dried out now but still around the same size when I pulled it from the tank.

 

[ubasu]

OK, I agree probably nerite snail eggs. I google some pictures and they look the same. I also added 10 nerites sometime last month. Thanks @unchaotic

 

[unchaotic]

Yeah, I'd say that's the size my nerite snail eggs were. My wife has a freshwater nerite snail and the eggs look the same.