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Is a Nano Aquarium right for me?

In recent years, the nano aquarium section of the aquarium hobby has been exploding in popularity. With many small fish becoming more available in the hobby, increased popularity of shrimp and other inverts, and even a few striking new discoveries in the last several years, the appeal has never been higher. For many people, the convenience of a small home aquarium is very inviting; however, there are some potential difficulties to consider.

The definition of a “nano aquarium” differs from person to person. For this article, I will be referring to tanks between five and twenty gallons, with five gallon aquariums only being appropriate for a hand full of species. Fish aquariums smaller than five gallons are too small to keep any aquatic creature in long term, so they should be avoided if possible. I will also be referring to freshwater set-ups exclusively, as salt water is outside of my base of knowledge.

Let’s start with acknowledging the difficulties of a smaller aquarium. If you have been in the aquatics hobby for any amount of time, you have probably have heard the saying “bigger is always better” in reference to aquarium size. As with many sayings, there is definitely some truth behind this. The more water you have in an aquarium ecosystem, the more room for error you have. Most people acknowledge the even greater need for regular water changes to maintain proper water chemistry. However, you should also consider that smaller tanks are more susceptible to temperature swings. You should avoid placing them near a heat vent or near a drafty door that may cause them to become too cool. You should also consider heat when deciding on the type of light to use because some light fixtures can produce enough heat to warm nano aquariums. When considering which species to keep, you really must consider their adult size and level of aggression. While this is important for all aquariums, smaller aquariums can be less forgiving to overstocking as there is less room for fish to get away from one and another.

However, there are some real advantages to setting up and maintaining a nano aquarium. The reason that most people start with smaller aquariums is the cost. There are inexpensive options for nearly all the necessary components, such as heaters and filters. Many places even offer all in one kits for an affordable price. Also, you obviously need smaller quantities of several aquarium necessities, such as substrate or necessary chemicals, which help to keep initial costs affordable. Due to their small size, these aquariums can fit in just about any home. However, you should make sure that you place it somewhere that can handle at least a little moisture as well as the weight of an aquarium.


When it comes to what to keep in a nano aquarium, the possibilities are endless. If you enjoy schooling fish, you could stock with many of the rasbora or smaller danio species. If you prefer more of a centerpiece fish, there are several apistogramma species that would do well in twenty gallon aquariums. Freshwater shrimp from the genus neocaridina are suitable for even the most beginner hobbyist, with just a little bit of research, and are available in just about any color imaginable. Some types of snails, such as mystery snails or nerite snails, can add a bit of color to the nano aquarium, while also helping keep things tidy. If you are looking for a fun breeding project for the whole family, many type of livebearers, such as guppies or endlers, can thrive in smaller tanks.

Live plants are a great accent in a nano aquarium. Aquatic plants are a great asset in these petite environments as they assist hobbyist in removing nitrate and other pollutants from the water, keeping the tank in better balance. It is easier to achieve high light environments for live plants due to the fact that nano aquariums have a shallower depth for the light to penetrate. There are even some all in one co2 kits to complete a high tech environment, though these are far from the most cost effective option in the long run.

Regardless of if you are new to the hobby or an experienced fish keeper, a nano aquarium can be very rewarding. There are certainly many advantages, as well as a few disadvantages. However, if you have a limit on space, or are hoping to enjoy the aquarium hobby on a smaller budget, a nano aquarium can be a great investment.

- Josh Phillips

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