Tropical Fish Tankmatests

If you're planning to have a community tropical fish tank first you have to know the type of fish that can live together. So choose ones with similar size, diet, and temperature. Choose a tank size suitable to fish as an adult. Always pay close attention and remove fish if they become too aggressive.

Some Guppies, Tetras, and swordtails are just some most peaceful tropical specials that happily swim around and easily adjust to newer groups.


  • Guppies are the most popular tropical species to keep in aquariums.
  • They are small in size and have colorful varieties.
  • Live up to 2 years and grow up to 2.4 inches.


They are extremely peaceful and friendly, except when their mating season begins.


  • They are peaceful, social, and easy to take care of.
  • They are most commonly known as green or red swordtails.
  • Average sized.

Why do fish fight?

Some fish species are greatly territorial than others, tanks are too small, and they fight for space. They start chasing other species to free up more space. Some fish can be highly competitive about food, plants, and Rocks. Many species are quite aggressive about their breeding rights. Some species of fish didn't share space and food due to their aggressive nature.

There are numerous factors to consider when choosing your aquarium, accessories, and decor.

Every fish will need some amount of space to be content, and the more space a fish has, the more likely they are to get along. The reason is, that fish are crowded together.

The age of a fish is also an important aspect to consider when building a community tank. Young fish can often be mixed with a wider selection of aquarium mates because they'll be more likely to accept them as they grow and nature.

Most fish will be opportunistic with food. That is why it is best to buy fish that are about the same size as the others in your aquarium.

Although one might not think of it right away, fish gender can also play a role in the ability of fish species to get along in a community aquarium.

Fish during the breeding time will take over large areas of an aquarium, usually pushing all other tank inhabitants into a corner. It is best to have a dedicated breeding tank in order to mitigate this problem.

Good community fish are those that easily tolerate other aquarium inhabitants because of either their size or their disposition, they pose no threat to each other or any other fish in the tank. That's good if you want a serene tank filled with happy, colorful fish.

Remember, too, that just because these fish are all peaceful it doesn't mean you can overcrowd them in a small tank. Stressed fish may Lash out at others. Stress is also one of the reasons aquarium fish die before their time.

Rules for stocking a fish tank

Avoid overstocking

It is important to understand the needs and tendencies of the fish you'll keep rather than simply relying on this formula. Do not overstock your tank and you'll have a much better chance of everyone getting along.

Choose tankmates wisely

Big fish eat little fish. It's usually that simple to be smart when choosing tank mates. Some fishes like the goldfish will provide a lot of colors and activity.

Other fish, such as shark fish, are less colorful but demonstrate very interesting schooling behaviors.

Oscars are dominant, large fish that don't generally tolerate other species' tank mates well. They will try to eat smaller fish especially.

Platies and goldfish for example are great beginner fish that enjoy living in community tanks.

Manage water conditions

When the conditions of the water are poor, fish get stressed. When fish get stressed, behavior issues are magnified.

Following are some steps to improve water quality in your aquarium:

  • Start with purified water. 
  • Don't over-feed the aquarium
  • Change chemical filter media.
  • Test the water.

When purchasing your freshwater fish tank, add a water conditioner about 24 hours before adding fish.

When changing your tank's water, do so weekly without a filter and every few weeks if your tank has a filter.

Fish that can't live together

The reality is that not all species of fish can live with each other due to their aggressive nature. Cichlids, certain species of sharks, loaches, knife fish, and other territorial fish do not share space well with members of their own kind or closely related species.


This aggressive fish from the South American Amazon does not let anyone stay with it.


These are really the best aquarium fish to stay alone.


These are the first fancy fish to be reared in tanks.