1. Do not overfeed the fish in your aquarium. Keep your feeding times at scheduled intervals to avoid overfeeding. If you are just starting your feeding routine, start out small and increase the amounts you put in on how much your fish eat.
2. You should always take the time to acclimate your fish to the aquarium. Acclimating your fish will get them used to the environment of the aquarium. Adding fish directly can be too much a shock for your fish and can pose health hazards.
3. Catfish sometimes require freshwater as juveniles and then as they get old they will need a more brackish environment. Make sure you read up on your catfish to learn what its needs will be when it gets older.