nano refugium

After searching for refugiums for my 20 gallon salt tank i found little to nothing that would work or was sold to fit that product need. I was wondering if anyone else has found a company that makes this, or has any experience making their own? I made my own using a breeder box then adding a...

So I just picked up a jbj rf 65 all in one tank, and I’m thinking of using one of the chambers in the back to build a nano fuge. Will it even be beneficial with a smaller amount of chaeto? I do eventually want a mandarin golby, so I figure it would be a good spot to house copepods. Thoughts?