I have a 40 breader and was wondering if a hang on ref was worth my time.Yea its small but with 7 kids its low budget .Lfs cuts me some deals and gives me somethging t0 do other thange diapers .
You can also make one out of a 10 or 15 gallon. I used a 15 gal for my 90, Put in some baffles to reduce bubbles. I have a section for the overflow and heater. one for cheato. one for the return pump and auto top off. Sadly this is too small for a protein skimmer.