Hello there. Interesting that you should ask about both these animals. I personally keep a 90 gallon that has 4 reedfish, and 2 senegalus bichirs:
The Senegalus is in fact my oldest fish (the gray female that you see in there).
Both animals are actually quite similar. The biggest difference is social preference, and of course size.
Bichirs in general really do require larger territories. For the smallest of their kind (the senegalus) you can do no smaller than a 75 gallon and that's just for one. The starting perm-home tank should have no less than 4 feet of length, and at least 18" of width. The wider tanks do better for these animals.
Social wise bichirs are territorial and...are usually not that social. They can however put up with each other when given a proper set up. This means a sand bottom tank, and having proper separate hide spaces set up. Having those places to retreat is very important. Once they become comfortable they may not use those places often, but simply having them there is a big difference between a cranky monster, and a peaceful tankmate. I have found over the years that if you place large sturdy plants into a tank bichirs will sometimes take to using those are resting/sleeping spaces. If your tank allows for room for such plants it's not a bad idea to plant a few larger species with good root systems.
Lastly keep in mind that these are not animals that you want to stuff and overstock into a tank. You may see people do it but it's often with no regard for the animals long term health or comfort.
Happy content sens are surprisingly easy to care for. Avoid feeding live feeder fish as they can lead to injury during the chase, are poor in nutrition, and if you keep multi-bichir can lead to nasty fights and increased aggression issues.
You can feed bichirs on chopped up worms, cubed tilapia, prawns, silversides, shrimp pellets, and other tasty odds and ends meant for predator fish. Avoid fatty fish, or beef. Both can lead to fatty liver disease if used in excess.
As for Reedfish, I am still relatively new in keeping these beautiful fish. What I can say is that when give enough space and kept in proper numbers these are truly wonderful to have. These fish are social, and can get to 18" or larger. My largest one is currently around 16".
Did I say social? Cuddly is more like it:
They feed well on chopped worms, shrimp pellets, blood worms, and even tilapia if cubed up into small bite sized peices. I am told they are shy feeders but mine seem to bulldoze and browbeat my bichirs who often let them get first bite.
These fish are heavily social. They need to be kept in groups. Not pairs. Groups. Like loaches, long term they thrive better when kept in good numbers. They also need places to hide and prefer to sleep in dens, and crevices.
These are very peaceful fish. You do not want to keep them with aggressive fish. You also want to be wary of their tank mates. Predatory fish can easily see a rope as a potential meal. Also schooling fish can make feeding these guys difficult. Keep their nature in mind. As with the Bichirs, these guys need larger territories simply due to their size and great length. Mine are in a 90 gallon, I wish I could move them into something like a 125. If you keep a group, shoot for at least a 75 or bigger. 4 foot long, by 18" wide minimum.
