how is your tank doing? do you need to reduce nitrates/phosphates, or do you just want to? Your pic looks pretty nice, I don't see any algae problems, so IMO don't fix it if it ain't broke. But, if you still want to do it, think about the atheistic, what will it look like in there, also...plan on running the lights with the tank, or on an opposite schedule? Finally, I once started a diy in tank refugium...macro algae got out, and I'll never be rid of it...so be careful there.