without a sump I don't see how a "sock" is going to function. If there is an intake you could use a filter pad or something if you changed it daily. I'm not a big fan of filter pad of socks but thats just me
Actually it has an overflow built into a very small
(1 gal?) sump built into the rear of the tank. Also, I have a chiller that returns into this thru a 1/2" rigid tube. Could I filter the chiller return water into an attachable sock filter? Is there such a thing?