I've kept my Clown Loaches at 80F for 29 years. Others often recommend 82F or higher but not usually less than 80F.
My Clowns have always eaten everything but I made a list of what I feed now.
My Clown Loach food recommendations: Clown Loaches are a river fish and in rivers they will be feeding on a mixture of aquatic larvae (my equivalent is frozen bloodworm and live aquatic larvae), aquatic worms (freeze dried earthworms), crustaceans (freeze dried pacific krill, frozen prawns, live daphnia) and molluscs (frozen mussels). I don't prefer processed foods but they love digging for their granules so I buy good quality branded ones. I use New Life Spectrum Algae Max, Tetra Sinking Discus Granules, Fluval Large Bug Bites, Omega One Shrimp Pellets and New Life Spectrum Large Fish Formula. Do not use cheap foods as they are not digested and just pollute your water in my experience.
My Clown Loach Food preparation: Freeze-dried Pacific Krill (the small one, the large one is Atlantic Krill) soaked in boiled water until they sink then rinsed. Frozen Bloodworms thawed and rinsed (I get a 1kg A4 sized sheet, chop it up with a hammer and chisel and box it in the freezer). Cooked Frozen Mussels or Prawns thawed, rinsed and chopped. You must buy them cooked so that the thiaminase is destroyed and supermarket ones usually state this on the packet. Freeze-dried Earthworms soaked in hot water and rinsed. I rear daphnia and aquatic larvae in my outdoor water butt.