Hi there, I just I would add that my 5 Hillstream loaches did take a little while to adjust to tank living. They do enjoy a nice current flow with cool, oxygenated water.
I have been using both 'Hikari Sinking Wafers ' for bottom feeders and 'Hikari Algae wafers' as staple foods for them. They also enjoy frozen bloodworms too. Although I have dropped sinking shrimp pellets into my tank, I have not observed them eat those yet. They also seem to enjoy 'Hikari Sinking Carnivore pellets' also.
You might not ever see yours very often if there is only one, especially if it is a recent addition. It wasn't until I bought 5 of them, and they adjusted to their new home that I started to see a more social behavior.
They also room with 5 Yoyo loaches which are very greedy eaters (who have also taken a liking to bottom feeder pellets) which I think has taught them to be more assertive when it comes to food. They can actually cover the top of the pellet/wafer which the others can't do. They don't go hungry.
If your setup will allow for it, try to add a power head pointing onto either some smooth rocks or some driftwood. At some point you should see your loach migrate to that area. AFAIK these guys are all wild caught, so mimicking a stream or some current helps them to adjust.
If you can (if you have room), try to get a few more. You can tell I like multiples of 5.
I hope everyone's info helps you out. There are a limited number of articles about them that I have read, but they all revolve around the same ideas of the river tank.
Cheers!
Algae on their diet is another very important part which you should be able to produce with ease. Just place a bucket of water with smooth rocks under direct sunlight. An additional pinch of fishfood will naturally speed everything up.
