i say up the temp to 30C, water change gravel vac and treat the tank with treatmenthey
right well
the tank is far far too small for a clown loach, they need to be in groups of 3+ and can reach 8-10 inches! so you will need a larger tank
its good you have no ammoniai say up the temp to 30C, water change gravel vac and treat the tank with treatment
good luck!