Surface Bubbles

[LeShrimp]

I have noticed in my tank that there are a lot of bubble on the surface. Any ideas why?

[Harry]

I get that too. Sometimes snails make the bubbles. But there is an entire system of biofilm and algae at the surface. From time to time, my Opae swim upside down at the surface, feeding off it. I think of them as skywalkers when they do that.