Temperatures between 65 75F are best for Hillstreams, no higher. Oxygen does not dissolve so well at higher temperatures so keeping them in lower temperatures is best for maximum Oxygen content in the water, Hillstreams Loaches require very high oxygen contents in their water so this is best. Because of their natural enviroment of fast flowing streams the oxygen content is always high, however, because this fishes range from habitat to habitat there is likely to be some difference in temperature for each species or habitat a species lives. Don't forget they also like a fast current and plenty of smooth stones for them to latch onto and sometimes feed, an established tank is best for them so the micro organism algae growths they feed on can be in good supply.
