chaeto and skimmer in sump

my plan was to build a three chamber sump. chamber one would be the overflow and skimmer, chamber two would be some chaeto and the last chamber the return. well all this has to fit in a 10 gallon tank in the cabinet underneath my 55 gallon. the ten gallon is the biggest i can fit in the cabinet and i really dont have room to build the three chambers like i would like bc my skimmer is a lil to big. would it be okay to just do two chambers one for overflow, skimmer, and chaeto and the other for the return or is this a bad idea and does anyone have any ideas i could try because im dumb founded. thanks in advance

Could you fit more then one 10 gallon tank under your stand?

If so you could line them up end to end. drill a couple holes in the glass and then connect them with bulkheads, pvc and union fittings.

Hmm, have you thought about making the 10 gallon just the sump (only two chambers, one for the skimmer and return), and making a refugium out of a HOB filter?

I dont have room for another 10 gallon how big of a hob filter does it need to be? i have two hob filters for 10 gallon tanks but i dont think that is goin to be enough

you could also get a smaller tank (2.5g) and build it kind of on a stand and use that for the refug ... there's a simple drawing attached

I have seen the set up BL1 is suggesting. A tank on top of a tank, you would need another pump, but it would work out and you would have plenty of room that way.