I have used a garbage can for a pond filter and I thought about using one on my 200 gal tank because the pond filter was working so well. Then disaster, the garbage can split and dumped water every where, of course the pump kept running and emptied the pond to about 3". I would find a 55 gallon drum that was made to hold liquid. I have a 55 gal. drum that was used to hold Pepsi syrup. Check Craig's list, in my area there is a guy selling safe 55 gal drums for $17.