Your tank is too small for Clown Loaches, they grow up to 35cm and must be kept on schools of at least 5 or 6 individuals so they need at least 500L!
Remember to use the ich medicine on a separated hospital tank, you don't want to kill your filter's bacterial colony with the med!
Provide all water parameters so we can help you better. That rock that you have there seems like a calcareous one, what's your
GH and
KH?