i have an mbuna tank with a few catfish and yo-yo loaches. for a few days they have been scratching but i dont see any signs of ich or any other parasites. i just did a large water change and added salt. but i think a medication would be the best thing due to the amount of scratching that is going on in the tank. now my question is what meds are safe to use with catfish and loaches in the tank for parasites?