Blacking out walls in clear sump

[Jdubbs0128]

Anyone have any products that are reef safe to black out the walls in my sump for a refugium?

 

[Waboss]

I'm assuming you mean the inside walls between chambers. I'd just order some acrylic or styrene, and cut it to match the divider. You can just place it there or silicone it (assuming the sump is dry right now). If you place it where the flow will help keep it pinned up against the clear divider, it should be ok. I did that for a while until I decided to DIY a sump and used black acrylic as the dividers.