Also remember Hillstream loaches like cooler temps so going with fish like White Cloud Mountin Minnows are a good choice. I have Red Lizard Loaches, which are a type of hillstream loach in with longfin WCMM. Which also brings up the fact that you can keep other types of hillstream loaches with them if you look up to be sure there aren't compatibility issues and if the tank has a large enough foot print. Look into Red Lizard Loaches (Homaloptera confuzona) and if you don't mind burrowing loaches the Red Tail Squirrel Loach (Aborichthys elongates) is one of my favorites. I'm trying to fix a tank so I can get some again.
Also Gold and Rosy barbs can tolerate cooler water but you need a big tank for Rosy barbs. Then Bloodfin and Buenos Aires tetras also can be kept in cooler water.
I don't have a heater on the Red Lizard loaches and Longfin WCMM tank.
You also will want to have algae covered flat rocks available or get and use a high grade algae food for them. I use Repashy Superfoods, both algae ones that make mixed together. They are powdered, mixed with boiling water, and can be refrigerated up to 10 days. It's easy to mix small amounts. I also use New Era Plec Pellets and sqeeze them down into a flater pellet before adding them into the tank. Then I also feed TetraVeggie Algae Wafers Extreme.
