Hi all of yopu,
this is Heiko Bleher and I am on my way again to the Amazon (and elsewehre) and I just wanted to give some experience with electric eels (Electrophorus electricus), as some of you seem not to know much about this unique Amazon-basin fish.
First of all it has so far mostly been kept in public aquariums around the world and millions of visitors look at those every year, with their discharge shown on a monitor (display). And that can be up to 800 V (not 500).
It is no problem to keep one or two in an aquarium of not to large size at all, and it will not grow to 8 feet in it (rarely more than 4-5, unless you have a giant aquarium and they are feed daily with large amounts of food). In a smaller aquarium they will adapt easily, although if bought in small size (some ship them in 4-6 inch size), they must be feed 3 times a day at least. And best is beef heart (cheapest), naturally blood worms, fish, shrimps, mussels, even granulate (larger) food they will take (some times need a few days).
If they are in healthy condition when bought or received (be sure they have no whitish slime, or white spots and that their mouth is not damaged), than they should give you no problem in a tank with fine white (or beige) sand and some driftwood. They are not much for plants.
When handeling, cleaning the aquarium, or having to go into it with your hand do ALWAYS were a rubber protection over your hands and do net get them wet. That is important and than nothing can happen.
I once had a couple of 5-6 feet long and in a very large vat. One day I forgot to cover my hands and took a hand net with a iron handle and it blew me 10 feet aways... It was my error. I never forget.
So just follow my advice if you want to keep one. They are extreme interesting and need to take in always atmospheric air, so they must always come to the top, and therefore the best is a open aquarium.
Best regards from one who knows, and collects,
and have alook at my website and my biotope aquariums: www.aquapress-bleher.com