20 Gallon Fish Tank – Tips & Information


A 20-gallon tank is ideal for beginners because of the ease in management when compared to a smaller tank that experiences toxin build up easily.

Novice fish keepers should, therefore, avoid the small tanks because water chemistry and temperature changes can occur very fast. They therefore, run the risk of making small errors that might not be reversible.

So what are the basics of a 20-gallon tank; for starters, it is very heavy at least over 200 pounds when full and it’s positioning has to be away from direct sunlight because of the risk of temperature changes, which is not healthy for the fish. Remember, with this huge weight you will need a stable stand rather than a desktop or a shelf. 

The type of fish that you keep in your 20-gallon fish tank should be considered. For beginners, it is recommended that you start with a small number of hardy fish and as you get conversant with their care routine, you can then add more. 

Benefits of a 20-gallon fish tank 

Because of its large size, a 20-gallon fish tank is an ideal breeding tank, as it will enable you to easily monitor and control water conditions. Besides when you mess up a 20-gallon tank is more forgiving than a small one. You can also use them to separate new fish or as a hospital tank when you want to treat your sick fish.

 With a 20-gallon fish aquarium, creative aquarists can decorate the fish tank as they deem fit. And incorporate as many tank decorations as they see necessary such as the hiding rocks, and caves, the live plants, and other tank accessories. 

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fish tank

Tips on Set Up

When it comes to setting up your fish tank, you have four options, you can either set it up as a community tank, a species only fish tank, a breeding or cold water tank. 

Community fish tank 

There is beauty in numbers and that is why many people love community tanks, you get to see how the different species of fish interact in one aquarium. The community fish tank needs to be peaceful for it to achieve the desired aesthetic value. You should, therefore, not incorporate big fish that will likely terrorize the small fish or even turn them into a delicacy. 

And did you know that with a 20-gallon fish tank, you could create an environment that is very similar to a particular area of the water body (biotope), complete with the type of fish that lives in the water body. The Peacock Bass is a perfect example of fish to include in a biotope aquarium and you will only need to add fish species that have the same water conditions requirement. 

Breeding tank 

As discussed earlier a 20-gallon fish tank is ideal for breeding only that you have to ensure that the species don’t have the ability to grow too big. The tank can be used with both the livebearers and the egg-laying type of fish. 

Single Specie

When you set up your freshwater aquarium the most common type of fish that you can keep is the goldfish. The problem with this type of fish is that only one species of the fish needs up to 20 gallons of water. That, therefore, means that you will only have one lonely and bored goldfish in the aquarium. 

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And on the brighter side pairing it with other types of fish might be challenging given its character of feeding on anything that fits into its mouth. They, however, come in different fancy types and you, therefore, have many options to choose from. 

Species tank 

The advantage of keeping a species tank is that you don’t have to worry about requirements that may vary when keeping different species of fish. With a species tank, you can, therefore, focus on fulfilling the requirements of the particular fish. For example, if you are keeping the schooling fish, you will be able to ensure that you bring out their best colors, which will also ensure that your aquarium achieves its cosmetic look. 

cleaning aquarium

Equipment for a 20-gallon fish tank

Water heater

The only viable method of controlling water temperatures in an aquarium ecosystem is to incorporate a water heater into your fish tank. The benefits being that it will keep your water temperatures at a constant level, preventing the growth of toxins, and the brown algae

Water filter

Your fish could simply succumb to its own poop and pee, the reason why you should include a water filter in your fish tank. Water filters aerate the water and reduce the speed at which toxins build up. The filters come in different designs, for example, we have the power filter that uses the disposable cartridges, and usually, hang on the back edge of the aquarium. 

The below 20 gallons fish tanks can effectively utilize the internal filters that are normally placed inside the aquarium to enhance water movement. 

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Aquarium lights 

Lighting in your fish tank, serves a variety of purposes, for one it will help to illuminate the beautiful colors of your fish; some aquarium plants need light for growth and it also aids in the growth of algae, which is food to different fish types. The type of light that you adopt for your fish tank largely depends on the type of plants and fish in your aquarium. 

Not all plants and fish require the same amount of lighting and you should, therefore, do a thorough research on your aquarium dwellers, to invest in the correct lighting. 

Fish tank hood

The importance of a hood is to prevent your fish from escaping, to nowhere of course, because they won’t get far without water. But we also need them to stay put in the aquarium; another reason is to prevent unwanted things from falling into the aquarium that might interfere with the water PH. 

Types of fish to keep in a 20-gallon fish tank

When it comes to stocking your fish tank, it is important to ensure that the fish are compatible, and won’t outgrow the tank. Water conditions should also be uniform for your tank dwellers, besides you have many options to choose from some of which are the mollies that come in a variety of colors, the neon tetras which are an attractive schooling fish and the bottom-dwelling cory fish.

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