There are many aspects to think about when selecting which fish you should put in your community tank. One big aspect that gets overlooked is making sure that you have a diverse group that fill the tank. Most kinds of fish will have a preference on where they swim. Some fish will stay on the bottom of the tank, some will remain mainly in the middle, and others will have a tendency to stay near the surface. To make the tank look full, one should try to get fish that will get along from each category.
3 Common Top Level Community Fish
Hatchetfish are a great selection for community tanks. There are a few different kinds you could find, the most common probably being the Marble Hatchetfish. These fish are very peaceful. Due to them not getting larger than 1 ¼ “ and having long fins, they can be susceptible to harassment from semi-aggressive fish. This fish shouldn’t be with any fish that are known tail nippers.
Dwarf Gouramis can be a focus point to any aquarium. These fish will breath air directly from the surface, instead of through their gills. They are peaceful and very shy fish. If you do have a pair of them, they will likely swim together as a pair. They reach only 2” when grown. It is important to not confuse these with normal Gouramis who will grow much larger. Dwarf Gouramis come in a range of colors depending on the hybrid mix you get. They can be kept with other non aggressive fish. There is a chance that a male will see other brightly colored fish in the aquarium as a potential rival, and become aggressive with them.
Guppies are another trademark fish of the aquarium hobby. These fish can be found in nearly any store. The males are very colorful with long fins. The females are not nearly as pretty, often dull silver colored. Guppies are a hardy and peaceful fish that should be kept in groups. These are also considered one of the easiest fish to breed.
3 Common Middle Level Community Fish
Neon Tetras are a signature fish species for the freshwater aquarium hobby. They are one of the most common and famous species available at nearly every pet store. Neon Tetras are very social fish and should always be kept in a school of at least 3 or 4. They are very fast and agile swimmers. They are extremely peaceful and normally won’t bother any other fish. They stay small, not commonly exceeding 1 ½”. These fish are hardy and are recommended for any new hobbyist.
Zebra Danios are another extremely common and easy fish for beginners. These fish share many characteristics with Neon Tetras. They prefer to be in schools, are very peaceful, and are quick swimmers. Their signature black stripes add a different look compared to many other freshwater fish. They grow to be about 2” when fully mature and can be kept in tanks as small as 5 gallons, as long as there is good filtration.
Platies are also seen in nearly every fish store. That is because they are extremely hardy, peaceful, and popular. These fish also come in nearly every color imaginable. They are also very easy to breed and are a great fish to start with if someone wants to become a breeder. They get along with nearly every kind of fish. They reach anywhere from 1.5”-2.5” depending on their gender. They enjoy being in groups, but are not a schooling fish. They will not swim together like tetras, but should be kept in groups of at least 3. They require at least a 10 gallon tank to do well.
3 Common Bottom Level Community Fish
Cherry Barbs are a perfect bottom level fish for beginners. These fish are very peaceful and colorful. They can be skittish and anxious when they are alone, so try to keep them in schools. They prefer to have both open water to swim, and areas of dense coverage. They are extremely easy to keep and will get along with nearly all fish as long as they are in a school. When they are alone, they also can become slightly aggressive, and may nip at slower swimming fish. They should be kept in a tank of at least 10 gallons.
Red Tail Sharks
Red Tail Sharks are a semi-aggressive fish. These sharks can grow up to 6” and should be kept in at least a 30 gallon tank. They like having a lot of hiding spots. These fish all have very different personalities. You should only have one per tank because they become territorial with other sharks. Some RTS will be really aggressive and nip a lot of fish so they should be kept with fast swimming fish like tetras. Having an RTS is a gamble for a community tank. You may get lucky and have a peaceful one, or get a very aggressive fish. These fish are popular due to their shark appearance and their famous black and red color scheme.
Killifish are beautiful and unique fish. They can come in a lot of different colors and patterns. These fish get to about 4” when fully grown. They prefer the bottom of the tank because in their natural environment they stay towards the bottom of lakes. Males have a tendency to become aggressive towards each other. Females are more peaceful, but aren’t as colorful. If you keep one of each gender, then the male’s color will stay more vibrant. If a male is by himself, he may fade a little bit because he isn’t trying to impress any females. Killifish shouldn’t be in a tank smaller than 20 gallons. They also prefer to be in tanks that have low water flow with plenty of hiding spots.