Ideas for a sump...

[SCUBA_STEVE]

Hey everyone. This may not be practical but I am going to throw it out there anyway. I have a 29g reef tank with a deep sand bed and about 30lbs of live rock. So I am thinking I realy only have about 20g of water in the tank. Now the tank is not drilled and I would really like to incoroparte a sump into the system. So I am looking at a HOB overflow (any sugestions or experiences would be aprreciated on that topic.) Now, I have limited space underneath my stand so I would really only be able to add somwhere around 15g of volume to the system. So... what I am thinking is to just head down to Walmart or something like that and get a Tote that would fit under my stand. So really all I would have is one chamber (in there I would have my skimmer, some extra live rock, heater and a return pump.) I would really like to setup a refuge but I dont know if i'd be able ot make dividers/baffles in a tote like that and that small of dimenstions. Does this seems like a good idea to everyone of is this just a pipe dream. Any suggestions or opinions would be greatly appreciated.
Thanks,
Steve