Go to walmart buy one of the big rubbermaid food bins. Take it home catch the eel and put him in it with an aerator and top. Then you can clean the entire tank in peace. I know he is 28", but not impossible to catch. If you can take his cave out first that would be better. It will be alot of work, but way better IMO than an eel bite.
It would be entertaining to watch you try to clean the tank with him in there.
Similar suggestion, either that or catch out the eel and fill a ice chest with enough water to last him for a couple days and filtration, add a few drops of copper and it will wipe them out and any other inverts existing in your tank in a day or two tops.
Option B, remove the eel and about half of your tanks water, dump everything out of your tank including gravel and what not, rinse rocks thoroughly and any other tank decor, replace into tank, add water that was kept from the tank(snail free water) and replace eel in tank = no more snails
take a 500ml pop bottle and cut the top off. then stick the top back in upside down. add algea waffers and drop into the tank. leave overnight and remove hundreds of snails in the morning. I use this to remove MTS form my tanks. works great.
take a 500ml pop bottle and cut the top off. then stick the top back in upside down. add algea waffers and drop into the tank. leave overnight and remove hundreds of snails in the morning. I use this to remove MTS form my tanks. works great.