You may want to try this. Aquarium Salt, it has electrolytes that improves gill function and is a natural stress reducer. About 1 rounded tablespoon for every 5 US gallons. I had a friend put me on to this many years ago and you can buy it as small as a pint size (16oz) carton that looks like and opens like a pint of milk. Any pet or feeder's supply store should have it. Hope this helps!