How do I filter this sucker?

just throwing it out there -

I would use the sponges.

A cannister may not work at that low of a level.  Might have problems with sucking air.  Use Jeff's idea.

A canister filter has hoses that will hang on the back of the tank and only take up about 1" versus 4" with a HOB.

I use 4 hydro 4's in my 75's, that way I know I have plenty of bio and can clean out a sponge or 2 whenever I want knowing the other 2 have plenty of bio load to keep the tank going

You can even take the Hydro sponge filters and put a power head directly on them as they have a 1" lift tube.  No messing around that way!

Jeff

Thanks for the good avice Jeff. Specially about power heads. My budget thanks you! ;D

Several large sponge filters will do the trick.  They will do some mechanical filtration for you.  Sometimes to good of a job.  Plan on cleaning one sponge filter each week to keep them running well and not getting gummed up with debre.  With two large sponge filters you can easily keep the tank clean and healthy as long as you remember to clean one filter one week and the other the next week forever!  If you feed on the lighter side you may be able to wait a little longer inbetween cleanings.

Also, if you get a lot of debre building up in the tank because the sponge filters don't circulate the water and debre as well as a power filter then try adding a power head with a sponge on the intake.  Used power heads can be had for a few bucks at almost every swap meet.

Jeff

I have 2 75g tanks on a double tier rack. I use HOB filters on the top one, but I don't have room for a HOB on the bottom one. ( should not have placed it so close to the wall). This is a Malawi tank with 18 Demasoni, 9 y labs, & 5 asst peacocks.

Can I just use a large sponge filter without benefit of mechanical filtration? I would use a cannister, but it comes down to $ as most things do. Any suggestions ???