They tore down the freshwater section of the Foster City Pet Club and are selling the old acrylic tanks for $25 they look to be 2'X2'X16" (estimated), they look like they'd make good sumps or growout tanks.
I was there one day and they had a whole wall full, then went back and they were down to two really scratched up tanks. I was thinking about making a display fuge with one. But oh well, my bad for debating it
They look really nice in my garage though. I have my old fuge tank you can have if you want it. It is a little taller and not as deep but still very usable. Just needs to be cleaned.
I might take you up on that, I am trying to plan out a stand to hold a refugium and qt tank, I just have to figure out the plumbing since the fuge can't go under the tank, and my tank is all in one. Kind of limits me a little.
You could always run it remotely with a gravity drain and some sort of pump from the sump for a feed. You don't need and or want much turnover in a fuge. I might be able to give you some ideas from my many trials and errors and could probably give you some chaeto as well as the ball I have is getting ready to need a trim.
I have cheato in my display at the moment along with some codium taylorii. The main problem I've had with the all in one and a fuge, is how to do the gravity drain portion without drilling. I was thinking maybe a drilled HOB filter lol