While some hobbyists like to get as much room as possible for their fish to roam, others enjoy testing the limits of just how small of an operating ecosystem they can get. 5 gallon (18.9 L) fish tanks are usually known as the bare minimum for betta fish, but these tiny tanks can be bursting with life just as much as a bigger tank can.
Keep reading to find out what kinds of fish you can keep in 5 gallons and our top 4 recommended fish tanks based on quality, customizability, and customer reviews.
What can live in a 5-gallon fish tank?
While a 5-gallon fish tank might not seem like a lot of room at first, with some careful planning, it can be just as easy and exciting as having a larger aquarium; most 5 gallons fish tanks also come in a kit so the initial setup is usually easy and relatively inexpensive. Though small tanks are sometimes harder to keep balanced since water parameters can easily fluctuate, they do get to the point of being self-sufficient just like any other aquarium system.
Of course, you will be limited in what you can keep, but there are plenty of setups that work for a 5 gallon fish tank:
Planted shrimp tank
Planted shrimp tanks are extremely popular in pico tanks due to experimentation with the Walstad method. In short, this involves having a balanced aquarium where the shrimp supply the plants with carbon dioxide and nutrients and the plants provide the shrimp with oxygen. This is done by creating an ecosystem that is almost entirely self-sustaining by creating a layered substrate of organic potting soil and coarse gravel. The tank needs to be heavily planted with a good lighting system in order for nutrient import and export to be balanced, so an abundance of fast-growing plants is a must for this method to work.
Otherwise, shrimp can also be kept in a regular 5-gallon fish tank without the Walstad method, though a filter will be necessary; a sponge filter is much preferred as it gives an area for shrimp to graze on biofilm and greatly reduces the threat of small shrimp getting injured or sucked up.
Betta fish tank
A 5-gallon fish tank is one of the best sizes to house a betta fish, though some hobbyists still believe that it is too small to comfortably keep this species. As long as the tank has an appropriately sized filter that doesn’t have too strong of flow, an adjustable heater, and some safe decorations, then 5 gallons should be enough space to comfortably make your betta fish feel at home.
An additional snail or two might be added, though snail populations have been known to explode in especially favorable conditions, which can be overwhelming for a small aquarium. Some hobbyists have even had luck keeping various shrimp species in this size tank with their betta fish, but we recommend keeping your betta fish alone unless you have at least a 10 gallon (37.9 L) aquarium.
Pico goby tank (saltwater)
You may have been told that a 5-gallon fish tank is simply too small to set up a saltwater system. While they might require a lot more attention to make sure that everything is testing the way that it’s supposed to, the actual maintenance isn’t any more intense than that of a freshwater system; regular water changes, a good filter, substrate vacuuming, and smart planning will go a long way to making a small saltwater aquarium easy to manage.
One way to utilize a 5-gallon fish tank as a saltwater ecosystem is as a pico goby tank. There are many goby species that will do just fine in that small of an aquarium, like the neon goby or clown goby. These species of fish only do well in this size aquarium because they tend to only keep to one area of the aquarium and don’t free-swim like other fish; firefish, clownfish, and another small middle- and top-water column swimmers will need at least a 10-gallon fish tank to be kept comfortable.
Most saltwater gobies also form symbiotic relationships with pistol shrimp; symbiosis is when at least one of the two organisms benefits from the other. A 5 gallon fish tank dedicated to a goby and pistol shrimp pair can definitely be just as exciting as a larger aquarium!
Pico reef tank (saltwater)
It might seem daunting at first, but a 5-gallon aquarium is more than enough room to keep a saltwater reef ecosystem. However, we do not recommend this setup if it is your first time trying saltwater in general as everything that can go wrong will go wrong and only previous experience with saltwater can help prepare you for any problems down the line.
Pico reef tanks are a lot of work and require a lot of money to initially set up and keep thriving as time goes on. For these tanks specifically, temperature, alkalinity, and water flow are the most important and most difficult components to maintain due to such a small space and minimal water volume.
Most hobbyists choose to keep a goby and pistol shrimp pair in order to keep nutrients flowing into the aquarium to minimize dosing and to bring some other life to the system. The exact maintenance and equipment needed to sustain one of these tanks will vary from system to system, but lighting and flow will largely be determined by the livestock.
How big is a 5-gallon fish tank?
A 5-gallon aquarium is a pretty standard size and usually easy to find in your local pet store. They are usually rectangular and measure approximately 16 L x 8 W x 10 H inches (40.6 L x 20.3 W x 25.4 H cm).
Is a 5-gallon fish tank good for a betta?
A 5-gallon fish tank is the bare minimum aquarium size for comfortably housing a betta for long periods of time. This tank should have a heater, filter, thermometer, substrate, lighting, and natural decorations. 5-gallon fish tanks make for easy water changes which will need to be performed weekly or biweekly.
If you feel like spoiling your betta, even more, 10-gallon fish tanks will allow more room for them to thrive. For the best tank options for keeping a betta fish, make sure to check out the list of our top five betta homes here.
Our top 4 fish tank choices
Here are our top 4 choices for 5-gallon fish tanks based on quality, customizability, and customer reviews. Many of the options are part of an all-inclusive kit; all tanks may be used for either freshwater or saltwater purposes with some modifications.
Tetra Crescent Acrylic Aquarium Kit, Energy Efficient LEDs
- aquarium KIT Curved-front crescent-shaped aquarium kit is perfect for one goldfish or up to three community tropical fish
- INCLUDES FILTER Includes Tetra Whisper Internal Power Filter to keep your tank clean and provide a healthy environment for pet fish
- HIDDEN LIGHTS Bright-white energy-efficient LED lights are hidden inside the low-profile black cover
The Tetra Crescent Acrylic Aquarium Kit, Energy Efficient LEDs is an attractive bowfront fish tank that is ready to house an assortment of species at an affordable price. These acrylic tanks measure 15 L x 9 W x 11 H inches ( 38.1 L x 22.9 W x 27.9 H cm) and fit nicely into smaller areas. They include a bright white LED lighting strip attached to an overhanging arm, a Whisper Internal Power Filter, a medium Whisper Bio-Bag Filter Cartridge, and a plastic lid; the included LED lighting is not strong enough to support live plants.
Customer reviews find the filter to be quiet and appropriately sized for the tank, though some hobbyists had to lessen the water flow for betta fish in particular. Many have complaints about the lid easily falling into the tank and the lighting being too strong at a fixed height due to poor design. The acrylic is also not the best quality and is often easily scratched and left dirty by suction cups. Otherwise, these fish tanks are perfect for keeping smaller species especially if the lid is kept off.
What we like:
- Sleek bowfront design
- Included filter and media
- Quiet and not-overpowering stock filter
Room for improvement:
- Poor-quality material for tank construction and lighting structure
- Lid easily falls into the water
- Water current from the filter sometimes overpowering
Top Fin® Engage™ 5 Gallon Aquarium
If you don’t mind glass instead of acrylic, then the Top Fin® Engage™ 5 Gallon Aquarium might be a better choice for the money. These beautiful glass aquariums are designed with ease and aesthetics in mind with HydroChange Technology; the interior back panel and bottom panel are white plastic.
These tanks measure 16.00 L x 8.58 W x 11.20 H inches (40.64 L x 21.79 W x 28.45 H cm) and make water changes easy and simple with a retractable outflow spigot. These glass tanks also include an internal filter with chambers for mechanical, chemical, and biological filtration. White LED lighting strips are also attached to the plastic hood, which can support some easy live plant species.
Reviews find the return flow to be a little low, but reasonable for betta fish. Otherwise, an additional source of water current will most likely need to be added. Most hobbyists also find HydroChange Technology to be easy convenient for small fish tank maintenance, but not enough to keep the ecosystem completely in check.
What we like:
- Compact all-in-one glass design
- HydroChange Technology for simplified water changes
- Included white LED lighting for some plants
- Large internal filter chambers
Room for improvement:
- Slow return flow from the filter
- Plastic bottom panel
- Additional equipment not included with the kit
MarineLand 5 Gallon Portrait Glass LED Aquarium Kit
The MarineLand 5 Gallon Portrait Glass LED Aquarium Kit is a favorite fish tank for new and experienced hobbyists alike. These tall glass tanks measure 11.81 L x 11.62 W x 17.05 H inches (30.00 L x 29.51 W x 43.31 H cm) and have rounded corners; the tank is also positioned on a raised platform to really highlight your saltwater or freshwater ecosystem.
The tank is designed with an overhanging LED light programmed with blue and white LEDs and the option for moonlight mode to provide a larger spectrum in order to support live plants and some corals. This aquarium features an internal filter that allows for mechanical, chemical, and biological filtration in different chambers. A glass lid is also included and sits comfortably on top of the aquarium to lessen evaporation and keep fish from easily escaping.
While most reviews appreciate the customizability of this aquarium kit, some hobbyists have had problems with small fish and invertebrates being sucked in through the intake slots. The taller dimensions also make aquarium maintenance a little more difficult and might limit the areas where plants can grow due to lessened light penetration.
What we like:
- Easy to set up and quality glass design
- Above-average lighting fit for freshwater and some saltwater
- Includes sleek glass lid
Room for improvement:
- Tall dimensions for limited access
- Larger intake slots that can suck up fish and invertebrates
- No additional equipment included with the kit
Fluval Spec V Aquarium Kit, 5-Gallon
One of the most expensive fish tank options available right now is the Fluval Spec V Aquarium Kit, 5-Gallon. These glass aquariums can easily sustain pico reefs and an assortment of freshwater plants. They measure 20.5 L x 11.6 W x 7.5 H in (52.0 L x 29.5 W x 19.0 H cm) and are available in a black or white-themed peninsula design. These tanks also feature an internal filter with dedicated chambers for mechanical, chemical, and biological filtration. The return pump is well designed and adjustable to meet water flow demands.
The aquarium kit also includes a 7000k high output LED that can support a variety of live plants and some corals; this light can also be switched to moonlight mode, but other blue and white lights cannot be independently turned on and off. Some reviews find the arm support for this light to be flimsy and will need some tinkering to get stable. These glass aquariums also include a pre-cut plastic lid that allows for better light penetration and gas exchange.
Some other reviews state that while the return pump is adjustable, even the lowest setting is too strong for betta fish in particular. Similar to MarineLand 5 Gallon Portrait Glass LED Aquarium Kit, the filter intake slots can injure fish with longer fins and completely suck in smaller species. While the plastic lid allows for better light penetration and gas exchange, it also allows for fish to potentially jump out if frightened.
What we like:
- Well designed with enough space for customization
- Adjustable return pump and chambered filter
- Above-average LED lighting for live plants and some corals
Room for improvement:
- Above average price
- Plastic, pre-cut aquarium lid
- Larger intake slots for fish and invertebrates to be sucked in or injured
- No additional equipment included with the kit
Conclusion
A 5-gallon fish tank might seem to limit to some, but to others, it’s more than enough space to cultivate a mini-ecosystem! Some stocking ideas include a planted shrimp tank, a betta fish tank, a pico goby tank, or a pico reef tank.
No matter what kind of fish tank setup you aim for, it is important to start with a quality foundation that will last the lifetime of your aquarium. Before going to buy your 5-gallon fish tank, consider if you want internal filtration or external filtration. Also, keep in mind if you want to eventually introduce live plants or corals as you may or may not need to eventually upgrade the light depending on which kit you choose.
If you have any questions about this size aquarium, fish that can be kept in a 5-gallon aquarium or have had experience keeping a 5-gallon fish tank of your own, don’t hesitate to leave a comment below.
