20-Gallon Fish Tank Guide for Beginner

If you are new and beginner aquarists, a 20-gallon fish tank is perfect for you. It is big enough to hold a variety of fish while small enough to maintain without much difficulty. A fish tank of this size enables you to keep a variety of fish and a few plants and small animals like snails and shrimps.

Even though most beginners start with a 10-gallon fish tank, a 20-gallon fish tank is perfect. It is easier to keep the water level stable, which is a common problem among new aquarists. Also, a 20-gallon fish tank comes as a part of a kit. This makes it easier for beginners since they do not have to worry about the equipment needed.

It’s not only ideal for beginners but is also perfect for experienced aquarists. They can use it to set-up a small biotope tank or a breeding tank. You can use it as a hospital tank or as a quarantine to separate the new fish from the rest.

Most 20-gallon fish tanks are longer in length than in height and width. A typical fish tank of this size will measure as 24(L)x 12(W) x 16(H). These tanks are usually rectangular or cubical and are of acrylic or glass.

Equipment Needed:

1. Filter:

Most fish tanks need a filter for a variety of reasons such as:

-The primary function of the filter is to remove the debris from the water.

-It helps to aerate the water so that the fish can breathe.

-helps to remove the build-up of toxins that have built up in the tank.

It is important to know that the filter needs to maintain. Also, replace the media used in the filter every one or two months as per the instructions on it.

2) Heater:

A heater helps to keep the water temperature suitable for the fish. The need for a heater will depend on the fish in your aquarium. A tropical tank needs a heater, for example.

3) Lights:

Lights are essential in your tank for several reasons:

for visibility, it makes the fish in the aquarium visible from the outside.
It makes the fish visible in their different colors.
It helps to spot problems.
But the main reason is for plants and fish. Light helps to regulate them. It keeps their conditions like those they experienced in their natural habitat.

But, the type of light you use in the aquarium depends upon the kind of fish and plants you have living in it. For example; Honwort doesn’t need a lot of light.

4) Hood

Even though most kits come with a hood, if you don’t have one, you have to get hood that will fit your tank. The reason this is so important is that not only will it prevent the fish from jumping out. It will also keep anything unwanted from falling into the tank. Besides, it also stops too much water from evaporating.

Other Types of Equipment You Will Need:

5 )Gravel


7) Decorations,

8) Fishnet

9) A Gravel Siphon

10) An algae Magnet

Types of Fish You Can Rear in a 20-Gallon Fish Tank:

Now it is vital to do a little research before you go around fish hunting for your aquarium. You have to ensure you get fish that are compatible with each other. And, they will not outgrow your tank and can live in the same water conditions (ph and temperature-wise).

In a 20-gallon fish tank, the choice of fish is endless. You can rear any small fish in it. But here’s a list which might prove useful if you are looking for ideas.

1) Guppies: Many people prefer keeping only male guppies due to their vibrant colors. They can grow up to 2.5

2) Platies: these also grow up to 2.5”. It is best to keep one female per two males. These fish are fun and active.

3) Swordtails: they grow up to 4”, need a lot of swimming space and are generally peaceful.

4) Mollies: available in a variety of colors and calm temperament.

5) Neon Tetras: grow up to only 1.25, colorful, and keep in schools of at least 6.

6) Zebra Danio: beautiful striped fish, keep them in schools of 6.

7) Cory Catfish: gentle and dwell at the bottom. They grow up to 2.5”.

Set-Up Ideas:

It is crucial to keep in mind the compatibility of the fish you are planning to keep in your aquarium. Here is a list of four basic types of set-up ideas to get you started:

1) Species Tank: It is easy to focus on the specific requirements of the particular species. It helps to bring out their best colors and behaviors. Examples- Neon tetras, Killifish, and. Beta sorority.

2) Breeding Tank: if the species are the kind that doesn’t grow bigger than 3-4”, you can use it as a breeding tank.

3) Community Tank: If the different species of fish are compatible, you can have a community fish tank. All the fish should be able to thrive in the same water conditions, though.

4) Cold-Water Tank: the option is less for a cold water tank. Goldfish is the most common fish for such a tank. But, one fish requires a 20-gallon fish tank to itself. So you can have only one goldfish.

How to Set Up a 20-Gallon Fish Tank?

First, clean your tank. Then decide where you want to place it, try to keep it away from radiators and windows.

Add the gravel to your tank, followed by all the other equipment as well. Don’t turn anything on though till you’re finished setting everything up.

Place a bowl on the gravel and start pouring water in it. Once the tank is full, Put in your decorations and plants if you have. Then turn on the equipment.

Dechlorinate the water and add bacteria started, although this is optional. You need to let a good bacteria bed establish. It may take up to six weeks for that.

Before you add your fish to the tank, float the bag for 15-20 minutes, then add a cup of tank water to the bag every 10 minutes. When the bag gets full, and the fish have adjusted to the water, only then add them to the tank.

These are some basic things you should know before venturing to become aquarists. The type of tank also depends on your budget and purpose. But, these suggestions will give you a basic idea of how to set- up the tank.

You May Also Like:

10-Gallon Fish Tank Guide for Beginners
Fish Tank – How to Select the Right Tank and Fish

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