Black Ghost Knife Tankmates

[InvisibleRain]

Hello, all! I'm new to the site so I'm sorry if I'm posting this in the wrong area.

When I was a small child, I had a tropical community tank (I'm pretty sure it's a 20 gallon tank, I've never thought to check), but slowly lost interest as I got older. I kept it going until the last fish died and then put it in the garage for years.

I recently revived my tank, and due to my youthful enthusiasm, the beginning was very rough. I (stupidly) purchased two aggressive fish: a 'dinosaur' bichir and a black ghost knife, both of which were just a few inches long (max. 3 inches).

I discovered the hard way that the bichir had an endless appetite when he bit off a huge portion of my ghost knife's tail. I found the bichir a new home and, with lots of TLC, my ghost knife made it through.

He is now probably 5 or so inches long and eats a ton. He is very atypical in that he is out most of the time, isn't shy and doesn't bother other fish. He currently is only living with one male guppy, 5 ghost shrimp and a golden mystery snail.


Looking into the future, what types of fish will be okay to house with him? I plan on getting a larger tank this holiday season (probably 50 gallons)

 

[InvisibleRain]

More relevant information: the tank has an under-gravel filtration system (don't even know if it works) and I have a bubbler keeping the air oxygenated and moving- plan on getting a pretty powerful filter soon. It is pretty heavily planted. I bought a tiny little baby plant (not sure what it is, looks pretty generic) and now I have 5 big adult plants

 

[CAPSLOCK]

I have no experience with knifefish, aside from what I've read. Something that isn't bite sized but also isn't going to bully the knife. Liveaquaria.com has pretty good information on fish, so a good place to research and get ideas.

Some thoughts:

Something like rainbowfish, once you've gotten the bigger tank (I think 20g would be kinda cramped for the larger ones, and smaller ones could end up being knife-food).

Maybe silver dollars? Those guys are herbivores so need a different diet than your knife though.

More expensive, but a really nice looking fish is the denisoni barb (also called the roseline shark).

Another option, if you don't want to keep the guppy or ghost shrimp, would be a leopard ctenopoma (leopard bush fish). Cool, not real active, ambush predator.

 

[InvisibleRain]

I was actually looking into rainbowfish for when I get a bigger tank. I really do like my humble little shrimp and hope to keep the tank peaceful as my ghost knife is not yet the bloodthirsty killer he is supposed to be.

 

[CAPSLOCK]

I've had the dwarf neon praecox rainbows before and they really are quite nice. Active and peaceful. More interesting than tetras IMO. They seem pretty similar to their larger cousins. Praecox rainbowfish may do well with the knife since they are fast, not sure if he would try to pick them off at night though as he got bigger. I would think the larger guys like bosemanis, turquoise, reds, etc. would be safe regardless because of their larger size. You can mix and match these guys, but they do like to be in a group / school.