Which Fish to Put Together in a Tank?

Aquariums are beautiful assets in any home. Watching how the fish swim around and hearing the sound of the water filter can have a relaxing and calming effect. You can literally stare at it for hours so if you have other pets and don’t want fleas to disrupt this beautiful scenery you should use a powder for furniture and a good shampoo for your furry friends.

After you are done setting the tank up, filling it with water, accessories, and everything that is needed, you need to put in your little companions. There are so many breeds to choose from, one more attractive than the other.

While it is true that the more varied they are, the more beautiful the whole installation seems, you must be very careful what species you put together. In one of our recent articles, we mentioned just how important it is to do your research before beginning such a project.

Space

Before we go any further, there is a significant observation to be made. There are thousands of freshwater breeds out there, and only some of them can live in a fish tank.

Still, there are enough to choose from. Even by selecting one from each species, you can end up overcrowding your aquarium. You should know that it is essential for each fish to have its own space.

Your fish may not be in their natural habitats like rivers or ponds, but they should not feel pressured either. After all, it is not a prison! An overcrowded tank does not even look good, so make sure you select only the recommended number for the size of your aquarium.

The common rule of thumb for fish capacity is between a half and an inch of full-grown fish per gallon of water. This number depends on fish breeds, filtration, and your tank management.

Preparations

As previously mentioned, setting up a fish tank is an entire process. You do not just get the product, pour some water, and throw in the fish. No, there are more actions required and a lot of research to be made.

The location is important — you have to set the aquarium in an area without direct sunlight, or it will cause excess algae, and you have to place it where you can easily manage it for cleaning and changing the water. You also need to make sure that the tank is at an even level on the stand, or else it might crack. Then, you need to get the proper water filters and safe accessories.

Afterward, you have to get an answer to the real question here — how do you create the appropriate habitat for multiple fish types? The answer is quite simple; it is the practical part that is more difficult. Basically, species that thrive in similar water chemistry and similar temperatures get along well.

Water temperature

It is recommended to go either with warm or cold water fish. You need to select species that all thrive at around the same temperature. Only a difference of a few degrees can be accommodated, or your small companions will suffer. A cold water fish will not live comfortably alongside a tropical one.

You must also adjust your tank equipment according to the fish’s needs, as some require lights and heaters, and others do not. If your tank does not sustain the right temperature or the appropriate equipment, some of the inhabitants can easily become more susceptible to disease. They can also move slowly and even refuse to eat.

pH levels

After we cleared things regarding temperature, the fish you select should have similar pH level requirements. Many types of fish you purchase directly from a store are adapted to a neutral pH, but they will always do better if the level is customized for them.

A tropical African cichlid, for example, thrives in alkaline water — most freshwater fish fancy levels between 6.5 and 7.5.

Moreover, you need to consider the pH requirements of any living plants you want to add to your aquarium. Many freshwater plants require pH levels in the range of 6.0 to 7.5, which is a reasonably wide range.

Eating patterns

It is highly recommended to put together only fish with similar eating patterns. Some species will eat anything in sight, including other, smaller fish. There are those picky ones that will refuse to eat if dominated by others.

Some fish need a pinch of flakes, whereas others require a certain number of pellets. Make sure you know about the nutritional requirements of the fish you want to buy.

There is another aspect to consider in this discussion, and that is the algae needs. Plecos, for example, are friendly algae eaters until their food is unavailable, when they become more aggressive.

Fish that live together

Many freshwater tropical breeds can live together in the same tank with no issues. We can name a few that are referred to as peaceful — Catfish, Corys, Danios, Gouramis, Guppies, Loaches, Mollies, Platies, Plecos, Rasboras, Swordtails, or Tetras.

Within these species, some of them are better adapted to living in groups than others. If your eye is caught by a specific fish, before putting it together with the ones you already have, you need to do some research and find out with which species it is compatible, and how well it could live with others.

Another recommendation is to avoid having the same species female and male together in the same aquarium. They can breed easily, and you will soon have an overcrowded tank.

Fish Schools

Another option you have is to keep fish schools of the same breed. Although some of them can live peacefully with other species, they would rather be in the company of their own kind, and they are happier and healthier if kept in schools.

Having a school of at least four or six of the same type of fish can add dynamic interest to your tank. If you decide to enlarge the number of a school, it is recommended to reduce the overall schools in order to prevent overcrowding.

In case you encounter issues setting a peaceful community, you can keep a single-breed tank with a large and energetic school in mind.

Coldwater vs. freshwater environments

While you might be tempted to stock your aquarium with the most beautiful fish your money can get, you will first need to think of the environment that your fish require in order to thrive.

As we mentioned earlier, the temperature of the water is very important so you should only pick fish that live in cold or warm water. You can’t place a coldwater fish with another that requires a heated aquarium. 

As a general rule, heated aquariums offer more varieties of fish to choose from, so even as a beginner if you want to have more choice, a heated tank should be the go-to option.

Coldwater freshwater fish that can live together

With that said, you do have some beginner-friendly options for coldwater freshwater aquariums as well. Coldwater fish such as Goldfish, Bloodfin Tetras, and White Cloud are the most popular ones. Goldfish come in a wide variety of colors and sizes and this is one of the main reasons why they are so popular, not to mention that they are one of the easiest fish species to look after.

Goldfish can tolerate temperatures that range from 62 to 74 degrees Fahrenheit and their only problem is that they tend to be messy eaters, which means that you should change 10% of the water each week.

Bloodfin Tetras are small fish that are appreciated for their silver bodies with striking red fins. They are hardy fish, and as long as you are careful with them you can expect them to live up to 10 years. They are very active and they move a lot, making your aquarium look very lively.

Bloodfin Tetras thrive in temperatures that range between 64 to 82 degrees Fahrenheit and while they are peaceful fish, they do like to live in a group so they will benefit from having a few companions of their own. If a Bloodfin Tetra is left on its own in the aquarium, it will tend to be shy.

Another small fish that can tolerate cold temperatures is the White Cloud Mountain Minnow, and since it can tolerate temperatures as low as 60 degrees Fahrenheit, some people choose to keep it in outdoor ponds over the summer.

Just as Bloodfin Tetras, these fish are hardy and can live up to 5 years if they are provided with proper care. They also prefer to live in a group, and it is recommended to purchase at least six of them if you want to promote good health and color.

Heated freshwater fish that can live together

A heated tank allows you to keep a wider variety of tropical fish and the typical temperature found inside such an aquarium ranges from 72 to 82 degrees Fahrenheit. To make it easier for you to decide, below we’ve presented six easy-to-care freshwater fish that can live together in a heated freshwater aquarium.

Danios are good choices for both beginners and more experienced fish parents since they do well in a variety of conditions and they are quite hardy. They are small yet very active and they prefer to stay in a group near the surface of the water.

As far as coloring is concerned, they have beautiful horizontal stripes that will catch the attention of anyone looking at your aquarium as they zoom around the surface of the water. Additionally, you won’t have to worry about food since these fish are not picky eaters and you’ll be able to use most types of flake fish food.

Platies are another popular choice since not only are they very easy to care for but there are also many varieties from which to choose and they do very well in a community tank with other passive fish.

It shouldn’t be too difficult to find one variety (or more) that suits your taste since Platies are bred selectively to create unique colors. They will eat most flake or freeze-dried food, and they will also keep your aquarium clean since they like eating the algae in your aquarium.

Swordtails are closely related to Platies and they come with a variety of colors that you can choose from. They are long-lasting fish, and they are not hard to care which makes this species perfect for beginners.

While the males have a long bottom fin that may make them look aggressive, they are in fact passive fish that do very well with other species that share their needs.

Betta fish are one of the most popular choices for heated freshwater tanks since the males have fins that are long and brilliantly bright. If you’re looking to add more flash and color to your aquarium then getting a few Betta fish should do the trick.

While other species do well in a group of their own kind, you should only get one Betta in your tank since they tend to fight with others of their kind. Despite their exotic and brilliant look, they are not picky eaters and they will eat most flake foods or pellets.

The Black Skirt Tetra is another peaceful fish you may want to consider adding to your heated aquarium. They should be kept in either a pair or in a large group. They will eat pretty much any food that you can find in the stores and they tend to swim in the middle of the aquarium. You may want to include a few rocks or plants to give them places to hide.

Speaking of places to hide, another species you may want to consider is the Kuhli Loach which is an eel-like fish that is a bottom-dweller and hides during the day. It likes to tunnel in the gravel and hide in caves or vegetation which is why it is recommended to offer it plenty of places to hide.

This gorgeous fish will also help keep the tank clean since it will eat the food that has fallen to the bottom. With that said, you should still offer it some food that sinks to the bottom since the leftovers from your other fish might not be enough to keep it well-fed. You should only keep them with other non-aggressive fish since Kuhli Loach are very peaceful.