Seeing a picture of your tank I understand what you are saying now. I think your tank might not be sump worthy. 
I am a huge fan of sumps and they are pretty much the only filtration system I will use. I don't see an obvious way to make a sump work on your tank. Maybe put a 20 or 40 breeder behind your tank on the fkloor as a sump??? Should work... should be better than trying to use a 50g drum.
A 20g sump is really a LOT of filtration if setup well!
You also might want to go to ebay and search for trickle filter. There are some really nice over tanks trickle filter options.
Your tank looks relatively new? I am guessing because your Pothos plants are small. I am also a big fan of Pothos! They are the best way to remove nitrates from your tank.
I am a huge fan of sumps and they are pretty much the only filtration system I will use. I don't see an obvious way to make a sump work on your tank. Maybe put a 20 or 40 breeder behind your tank on the fkloor as a sump??? Should work... should be better than trying to use a 50g drum.
A 20g sump is really a LOT of filtration if setup well!
You also might want to go to ebay and search for trickle filter. There are some really nice over tanks trickle filter options.
Your tank looks relatively new? I am guessing because your Pothos plants are small. I am also a big fan of Pothos! They are the best way to remove nitrates from your tank.

