Top off tank

[fishlips]

Got a question. I have been using a ten gal aquarium for top off for my tank. Not sure if its related or not ,but I have thin layer of real bright lime green stuff on the bottom of tank. The top off dose see a little sun shine.
Or could it be that i got a bare bottom tank and the fuge light is causing it from under the tank.

 

[tbub1221]

I'd guess fuge light probably , I have some mylar sheeting I put on my refugium glass to keep the grow light from splashing through and growing coralin algae in my sump and skimmer .
I've since removed the refugium but I think I have more mylar if you want to try it I'll look for some.

 

[fishlips]

Thanks, I will put something up under the bottom to shield it.