An aquarium filter helps keep the water clean and helps maintain the nitrogen cycle. Make sure your aquarium filter has the right filtration for your tank.
If your fish likes to school or shoal with other fish, you will likely need at least five others to help them feel comfortable. Make sure you have the space to house these extra fish beforehand. Not all fish need friends. Some fish, like Bettas, either need to be kept alone or strongly prefer a solitary environment. There are other ways to provide enrichment for these fish besides trying to give them unwanted friends.
If you have multiple fish, make sure all of your fish are getting enough to eat. Ensure none of them are getting bullied out of eating enough and that none of them are overeating.
