1. Goldfish require a PH level of around 7.5 to live comfortably. Use PH testing strips to ensure that the levels in your aquarium are just right.
2. 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.
3. Discus fish are very hard to care for, they have very specific care instructions. These fish are hard to care for but are very beautiful. However we recommend that these fish only be kept only by the advanced aquarium owner.