adding refugium, comments?

[mark]

Did the sunglass thing and don't see checkering so assume good to drill.

Thinking the crushed coral or coral chucks for pods as when I had a DSB, always seemed more pods on the rock than on the sand.

As for the overflow, since don't really have the height for the ref to drain downward first, the bulkhead with face outward then pipe will run horizontal for a least 16" before turning down. Any problems with this for flow? Noise really not an issue as in the basement but wondering about that as well.