Glad I came across this thread. I have been thinking about something like this for a while. I have a 55G tank that I am not sure if it is tempered glass or not. I am unwilling to find out that hard way, so I have pretty much ruled out a sump (best I can fit in the stand is a 10G tank anyway). I do like the idea of a refugium though as I do plan to add a mandarin down the line.

