As I posted in another thread. Find out the species of Hillstream Loach, get the Latin name and care guides will be more exact.
There are several species lumped under this and other Common names.
My club members say River Tank set ups are best. Or at least a Power Head. I haven't had one of these fish yet, but I've been researching them as I love the look of them.
Cool, Clean, Fast Flowing, well oxygenated water. Actual algae, you can rotate rocks to keep fresh Algae for them. YouTube has some videos.
I've read many accounts of them dying in regular Tropical Community Tanks. Too warm, not enough Oxygen or flow.
I hope to learn more as well. I found lots of care guides and forum threads on these fish.