Treating "Feeder Fish:"
The only downside to these fish is that, since they are sold as "feeder fish" or "bait," they usually have parasites and other health problems due to overcrowding and poor care. Medications and good care can reverse this. Pick apparently healthy fish with which to begin. To treat a newly bought batch of rosy reds, I used Aquari-Sol by Aquarium Products, Inc. at half dose (I have soft water) for four or five days in a 5 gallon quarantine tank where they remained for two weeks. I vacuumed water off the bare bottom daily and used a corner filter. Salt levels of about 1 Tablespoon per 5 gallons were used initially but diluted with the daily water changes. Extend the quarantine if any fish die.