The guy in the local pet store just wants to sell you a hill stream loach, fish tank, heater, filter…….. many keep more than one and I’ve never heard of they being aggressive. Theyre pretty much algae eaters/ waste eaters (left over food). They can also be kept in a wide temp range.
IMO, at least a 29 gal. tank. Loaches in general require excellent water quality. If you decide to keep Loaches, make sure to properly cycle the tank. Be sure to invest in a quality filtration system & be prepared to change out 25% - 50% of the water on a weekly basis.
Most Loaches do better in groups. Advice given from fish store employees are often erroneous. It's best to research on line & consult with forums members.
i keep a solo hillstream in my 29 gallon puffer community tank after reading on multiple sites that they will fight with other hillstreams over territory. seems unbothered, i see him constantly suctioned to different surfaces of the tank going about his business
I have a single hillstream loach in my 20g long community tank, because he was the only one my LFS had. I would prefer to have 2-3 more as they are social fish, but for now this is what we have. I have read that they can get aggressive during spawning, but otherwise they're generally peaceful and safe with a wide variety of other inhabitants. Mine does have some pretty hilarious food aggression. I use two food dishes for messy stuff like repashy and algae wafers and he has decided the contents of a particular dish are *all* his. Even when he's no longer eating he'll plaster himself onto the glass beside the dish and wait. If an oto or shrimp or danio dares enter his dish he flies off the glass and body slams them until they leave his dish. Then back to the glass to stand guard. Fortunately with his little sucker mouth I don't think it's possible for him to really injure anyone (or himself) with his antics. All that to say, can you keep them as singletons? Yes. Would mine maybe be less obsessed about guarding a food dish if he had some of his own kind to socialize with? Possibly. I'm a big fan of following the natural tendencies when possible - so if you have a naturally schooling/shoaling fish in an aquarium it's probably best for their health and happiness to give them a couple of buddies if you can.