I tried the filter routine myself with less than statisfactory results. I found it too much work to keep it primed and sealed. I keep my eels in a big brown plastic garbage can in the cool corner of my basement with a cheap aquarium aerater strip in the bottom of the can as well. I was going on a long vacation once (away from the shore) so I thought it would be a good idea to set up and old aquarium filter to keep the ammonia levels down while I couldn't change the water for better than a week. Well the first night trial run told me this was not a simple solution. Yes those eels will find the smallest opening and squeeze out. ( kinda like mice...how can they do that) You'll find them at a some later date... And yes, they will swim up the filter tubes and even the water discharge if not covered with a suitable material/device. The eels somehow managed to knock off the strainer on my pick-up tube. I think my next attempt might be to try some type of all enclusive (cheap???) water pond type pump/filter but for now I've kept the slimy guys alive for more than a month at times by just taking a 5 gal pail and scooping out as much of the "old" water as I can and replacing it with new (well in my case) water every couple of nights. Of course if the power goes out like it did this last August you better remember to get those guys out of the water or you'll have a bunch of dead eels like I did when I got home that dark night.
