why can't you use a bilge pump for a fat sac? they seem much cheaper and are 1500-2000 gph.

It would work for pumping into the bag, but you couldn't interface the pump with the 3/4" wterbed fitting on the fat sac.

i bought a pump at walmart and the waterbed fitting fits on it.

I have the pump from walmat also, just get the aeroator style. You'll need to wire a longer lead.

I got the one from WalMart also, but I don't think it is a bilge pump, but rather just a pump that has a threaded piece. All bilge pumps I've seen don't have the threaded portion on it.

I actually tried a 1400 GPH bilge pump from Wal*Mart once, and couldn't even get it to pump the water over the edge of the boat into the sac. Went back to my 700 GPH aerator style pump til I got a 1100. Now I am fully automatic with Simers.