Red tailed shark

Question
Hey there, any ideas on a companion for my red tailed shark?
he is on his own in a 20 gallon tank, plants, filter, rocks
and driftwood for him to hide in. I recently had a pair of
boesman rainbows with him but they have passed on, any ideas?
thanks for your time

Answer
Red Tailed Sharks are generally ill-tempered, territorial and can be very hostile toward other fish.

That doesn't mean there aren't other fish who do well with them, however you should definitely keep their size comparisons in mind when choosing.

I'd choose fast-swimming fish such as the Giant Danio, Cichlids - because they are also ill-tempered and generally won't allow themselves to be picked on, and African Cichlids.

When choosing a tank mate, keep in mind their "temperment" compared to his.  

Red Tailed Sharks are so beautiful, but they can become terrors if given the opportunity and the best way not to let that happen is to give them tankmates who can stand up for themselves.

I hope this helps. :)

Happy Thanksgiving.