10 Gallon Vs 20 Gallon Fish Tank – Which One Is Better?

10 gallon vs 20 gallon fish tank, which one should I get? Can one of them overweigh the other?

If you are still in two minds between these two options, consider the information in this writing. There is helpful insight, detailed comparison, and choosing criteria for you to make up your mind.

10 Gallon Vs 20 Gallon Fish Tank Review

Quick Rundown Of 10 Gallon Tank


  • Costs less compared to the 20-gallon type.
  • Less requirement for maintenance
  • Save more time and effort.
  • There are not many accessories required.
  • Suitable for the demand for small houses
  • Save much more time for cleaning.


  • The water community offered is more limited than the larger type.
  • Due to visual and capacity, you have to invest in a small number of fish of small size.

The same goes for decorating plants and stones.

  • The fish and plants can not grow to the big size as those living in the 20-gallon tank.
  • If you are into aggressive fish species, a small container of 10 gallons is irrelevant.


Source: Wikimedia Commons

Quick Rundown Of 20-Gallon Tank


  • You can have fish in bigger sizes and greater quantities.
  • The water community offered is more diversified.
  • There is enough space for territorial and aggressive species.
  • The need for water parameter modification is not apparent.
  • Animals and plants are allowed to get bigger.


  • More investment in devices such as powerful lights, units of water and air circulation, more filters, and other accessories
  • More expensive and requires more space
  • More time, effort, knowledge, and experience are required for maintenance.

Is A 10 Or 20 Gallon Tank Better?

Using Purposes

How do you want your aquarium to be? If you are into a spacious, stunning look of a diversified ecosystem, go for the 20-gallon type. You can equip it with numerous lightning and other accessories for displaying.

Moreover, there is less limitation in the quantity of animals and plants contained. You can even let them grow larger.

Meanwhile, if you prefer a simple tank with fewer requirements, purchase the 10-gallon type. It means you will go for the fish and plants in smaller sizes and quantities.

10 gallon tank

Source: Wikimedia Commons


Choosing a tank fitting your accommodation is crucial. If you are living in a big house with many counter spaces or even surfaces, you can definitely place the bigger type in it.

On the contrary, when there is not much room at your home, you’d better get a smaller footprint. However, make sure that the small storage still handles the aquarium inside.

Weight And Size

Consider the weight of these tanks carefully; then, you can choose a suitable spot in your house. For instance, the total weight of the empty container and the fish, plants, water, and devices inside would be too heavy to place on a desk.

Generally, a 10-gallon tank made from acrylic weighs approximately 10 lbs, while the glassy one weighs 13 to 15 lbs. The 20-gallon type weighs about 20 lbs of acrylic material and at least 30 lbs of glass material.

How many fish can I have in a 20 gallon tank? The dimensions (Long x Wide x Tall) of the 20-gallon type are available in 24 x 12 x 16 and 30 x 12 x 20. Thus, this type can accommodate 10 fish with 2-inch lengths or 20 of those with 1-inch lengths.

The other type has only one dimension: 20 x 10 x 12. How many fish can I have in a 10-gallon tank? There is no particular number offered. However, it is advised to keep eight to 10 tiny fish in this container.

Source: Wikimedia Commons


You should not raise fish having an overgrown adult size, waste generation, and aggressive tendency in such a small 10-gallon aquarium. The suitable species are betta, guppies, dwarf gourami, and zebra danios. All of these have a minor size and can survive under harsh conditions.

Meanwhile, the 20-gallon pool can manage a wide range of species based on your interest. You can go for swordtails, molly, platy, cory catfish, and even other aggressive species.

Experience And Knowledge

In short, the more experienced you are, the bigger tank you can purchase. Once you have knowledge about aquariums, you can manage a diversified community inside the tank.

On the contrary, hobbyists or novices should start with a small-sized container and a small quantity of fish as there is less effort and skill required.


As mentioned before, not to mention the cost of the containers, you have to invest in the devices, decorations, and maintenance fees. The smaller tank requires less investment for settings and offers simpler cleaning.

If you have certain spare time with a generous budget, get a 20-gallon one. On the other hand, a 10-gallon container is relevant for a more limited budget.

Water Quality

Generally, a quarter of the water inside needs changing each month. If you do not have enough experience, it is easier to guarantee the water parameters in a smaller container.

The same goes for the demand for warm water species. Specifically, the common water for these species ranges from 76°F to 80°F. Thus, people tend to place the tank next to their heater.

The 10-gallon tank can warm up faster than the others, thanks to thinner walls. Meanwhile, both choices are acceptable if you are into the cold water species.

Can I Use A 10 Gallon Filter In A 20 Gallon Tank?

No, it is not recommended. The small wattage of a 10-gallon filter can not manage the filtering and cleaning of a double-sized aquarium.

Moreover, due to the differences in dimensions, the filter can not move an exact amount of water to preserve the pet’s health and life.


Have you got your winner in the combat of 10 gallon vs 20 gallon fish tank? There is no particular answer for the better type. The pick-up one is the more suitable one.

Start your first step with a small container if you are a beginner. Meanwhile, professionals with proper experience should go for the bigger option to satisfy your hobby.