A 15-gallon fish tank is a perfect size for you if you’re new to fishkeeping, and you want to invest in a starter tank.
A tank that size enables you to keep a small selection of fish and invertebrates while showing you how to maintain a healthy environment for the creatures that live in it. Understanding water chemistry and knowing how to manage it is crucial to a healthy, thriving fish community, and a mid-range tank is an ideal way to get your head around all that before you move on to a larger setup.
A 15-gallon fish tank can also be used by more experienced hobbyists as a breeding or quarantine aquarium, or perhaps to raise live food for the occupants of the main display tank.
In this guide, we’ve picked out six of the available on the market today. We provide you with a selection of ten of the best fish species to keep in a tank of that size, explain how to set up your new tank, and more!
6 Best 15-gallon Fish Tanks
First of all, let’s take a look at these six 15-gallon fish tanks. We’ve included in-text links for you to the full spec for each product.
Hagen HG Fluval Flex Aquarium
- The Fluval 15 gallon flex freshwater kit is one of very few freshwater aquarium Kits to incorporate brilliant illumination and multistage filtration with convenient Aquarium features and contemporary...
- Item Package Height: 30.0
- Item Package Length: 35.0
Our first choice is the Hagan HG Fluval Flex Aquarium, dimensions 16″ x 15″ x 15″.
This glass tank is cleverly designed with a curved front to give the illusion of a much larger unit and also provides you with a better view of your fish. The honeycomb wrap detail hides the waterline, and the filtration equipment is concealed behind a black rear screen.
The tank has LED lighting, which is great for plants and also helps to show off your fish. The lights have a remote control feature, and there’s a range of colors and effects too, which can be useful for the daytime viewing of nocturnal species that would otherwise remain hidden away.
The aquarium tank has a powerful filtration system that keeps the water conditions healthy and stable for the wellbeing of the fish.
What we like:
- Comes with filtration system and LED lighting
- Stylish design with a nice bowed front for improved viewing
Room for improvement:
- Doesn’t have a heater, although there is space for one in the rear filter compartment
- Small fish could be trapped in the intake vent
- Not easy to change the lighting unit if you wanted to
#2 Coralife LED Biocube
- Sleek modern hood with vibrant LED lighting for freshwater to saltwater environments
- Integrated 24-hour timer with three independent channels bright white sparkling blue and color enhancing LEDs
- Automatic 30 minute sunrise/sunset and 60 minute moonrise/moonset functions to replicate natural day cycle
The Coralife LED Biocube is a premium aquarium of superb quality and design, dimensions 15″ x 16.8″ x 17.5″.
This tank is actually 16 gallons and fits in perfectly with any home decor scheme. A top-spec filtration system is included with the kit, and there’s LED lighting with several colors and brightness settings designed to enhance the colors of your fish. A neat feature that replicates the fish’s natural environment is the 30-minutes sunrise and 60-minute moonrise and moonset function.
The filtration system can be customized and incorporates an adjustable, dual intake submersible pump that’s concealed behind a screen at the back of the aquarium.
What we like:
- Superb quality and very well-made aquarium
- Easy to set up and comes with clear instructions
- Spacious concealed equipment chambers
- Modern and stylish design
- Great value for a relatively low price
Room for improvement:
- LED lighting is not great for plants
- Fan system inside the tank lid is very loud
#3 SeaClear Acrylic Aquarium Combo Set
- Combo includes aquarium, reflector and electrical 12" light fixture
- Tranquil Hexagon design; You won't believe how your fish and decorations will pop!
- Acrylic aquariums are clearer than glass, 17 times stronger, and only half the weight!
The SeaClear Acrylic Aquarium is a 15-gallon hexagonal aquarium, dimensions: 15″ x 15″ x 20″.
This tank makes a great choice to add interest to a corner or alcove in a room. The tank is built from strong, scratch-resistant acrylic material, which is more durable and lighter than a traditional glass aquarium, making this aquarium a safe option for you if you have a household with other pets and kids.
The tank has a 12-inch light fixture with a light-enhancing reflector.
The SeaClear brand is well-known within the industry for producing high-quality products, and this tank comes with an extensive warranty for your peace of mind.
What we like:
- Acrylic material is safer than glass around pets and kids
- Three optional background options to choose from at the point of sale
- Fully warranted
Room for improvement:
- Does not come with filtration or heating
- The lid is not removable, making cleaning tricky
#4 biOrb Classic 16-gallon Aquarium
- Constructed Out of Acrylic- 10 times stronger than glass, 50% lighter and 93% clearer
- True 5 Stage Filtration - Biological, Mechanical, Chemical, Water Stabilization and Oxygenation
- Low Voltage – All biOrb aquariums operate from a 12V Transformer
The biOrb Classic 16-gallon Aquarium is designed to resemble a traditional fishbowl. However, unlike those old-style glass bowls that were anything but healthy for your fishy friends, the biOrb has a powerful, five-stage filtration system that’s concealed in a compartment beneath the tank.
The tank is constructed from super-strong but beautifully clear acrylic. There’s also a standard LED light in the aquarium lid.
This neat, classic design is perfect for a home with limited space, while still enabling you and your family to enjoy the relaxing beauty of an aquarium in your home.
What we like:
- Beautifully designed, traditional-looking fish bowl-style tank
- Minimal maintenance required
- Five-stage filtration system for crystal clear, healthy water
Room for improvement:
- Difficult to clean
- Poor oxygen saturation won’t suit all fish species
#5 biOrb Cube 30 Aquarium with LED
- Stylish approach on traditional shape. Constructed out of Acrylic - 10 times stronger than glass, 50% lighter and has a 93% transparency rating.
- True 5 stage filtration - biological, mechanical, chemical, water stabilization and oxygenation.
- Unobstructed view of your Aquarium inhabitants. Led lighting - equipped with a long lasting, low voltage standard LED light.
The biOrb Cube 30 Aquarium is a 16-gallon fish tank, dimensions 15.7″ x 15.7″ x 17″.
The cube provides you with a totally unobstructed view of your fish and gives you lots of space for aquascaping. You can choose from black, white, or clear trim. Your fish are illuminated by remote-controlled, multicolored lighting that has no fewer than 16 colors to choose from. You can set the lighting unit to gently fade in and out through the entire spectrum, and you can control the brightness too.
Optimum water quality is maintained by the five-stage filtration system that’s easy and quick to maintain. The light and filter pump are low-voltage for safety and for your peace of mind.
The fish tank is made from strong, durable acrylic and is backed by a two-year, no-quibble warranty.
What we like:
- Acrylic construction is stronger and lighter than glass
- Excellent five-stage filtration system, including biological, mechanical, chemical, water stabilizing, and oxygenation elements
- Exciting, remote-controlled LED lighting system
- Easy, no-hassle maintenance
- Two-year warranty
Room for improvement:
- Doesn’t come with a heater
#6 Tetra 20 Gallon Complete Aquarium Kit
- Let the LED light transform your aquarium with each color change. Pause the cycle on any color to fully customize your aquarium
- The anemones sway with your filter current and give your fish a place to hide and relax
- Tetra plants come to life under the glow of Color Fusion LED
Tetra is a brand that comes with a mighty reputation for producing top-quality products for the fishkeeping industry. This fish tank is a tad over our 15-gallon limit at 20 gallons, but this kit does include everything you’ll need to get started with your new hobby.
The kit includes a full set of decorations for your aquarium, and you can choose from three different looks, depending on your preference. The LED lighting system includes color-changing technology that really brings your artificial plants, tank decorations, and fish to life. You also get a super-efficient and quiet-running Tetra Whisper filter system to keep the water in pristine condition, and there’s a heater too, making the tank suitable for tropical fish species.
The aquarium is built to last from scratch and chip-resistant glass and comes with a lifetime warranty. The tank dimensions are 24.2″ x 12.4″ x 16.7″, and everything is made in the U.S.
What we like:
- Well-respected brand and U.S.-made product
- Comes complete to save you money. All you need to add are fish and water
- LED lighting system with impressive color and setting range
- Lifetime warranty
Room for improvement:
- Filter unit becomes noisy after a few months, and some users complained that it failed or burned out
- LED lighting unit is difficult to operate
Essential components of a tropical fish tank
When setting up a fish tank from scratch, there are certain items that are essential for the health and wellbeing of your fish.
Like all living creatures, fish produce a certain amount of waste. That waste goes into the water or sinks into the substrate at the bottom of the tank. Fish waste, decomposing plant matter, and uneaten food, all produce ammonia. Ammonia becomes nitrite, and ultimately nitrate, which pollutes the water and is extremely harmful to the fish.
Bottom line; if you don’t keep the ammonia and nitrate levels as close to zero parts-per-million as possible, your fish will eventually become sick and die.
So, your tank must have a filtration system. You’ll need to maintain the system and carry out partial water changes of around 25% of your tank water every week to keep the environment healthy. Also, before introducing fish to the tank, you need to set everything up and allow the filter to run for ten days. That allows beneficial bacteria to colonize the filter media and get to work on cleaning the water before taking on the extra work of treating fish waste.
All of the best aquariums we’ve listed in this guide come complete with that all-important filter system that you want.
If you want to keep tropical fish and live plants, you will need a heater.
The heater can be set to keep the water at the optimum temperature for the fish species you choose. If the water is too warm, too cold, or the temperature fluctuates wildly, some species of fish will suffer from temperature shock, which could kill them.
So, if the tank doesn’t come with a heater, you’ll need to buy one.
If you have live plants in your tank, they will help to remove CO2 from the water and oxygenate it. However, if the tank is heavily stocked or of such a design that it doesn’t have much surface area, you may need to give things a helping hand by using an airstone fitted to a pump.
The pump pushes air down a piece of plastic tubing through the airstone and into the water, helping to add oxygen to the water.
Although an air pump is not essential, you may want to consider including one in your setup.
Decorations and plants
Your tank should have a substrate of sand, gravel, or marbles. A substrate provides an area where beneficial bacteria can grow, enables plants to take root, and is more aesthetically pleasing than a bare tank bottom.
Live plants also encourage beneficial bacterial growth, as well as providing fish with somewhere to rest and hide. If you prefer not to use living plants, you can choose silk ones instead. Plastic plants are available, but they can have sharp edges that could injure your fish, so silk or living planting is preferable.
Most fish species enjoy exploring and hiding in caves and the like. There are dozens of tank decorations to choose from, including natural rocks and driftwood, just be sure to wash everything thoroughly before adding items to your tank so that you don’t accidentally introduce diseases.
Ten fish species for 15-gallon tanks
Now that you have your fish tank set up and ready, what fish species do you want to keep in it?
In this section of our guide, we highlight ten of the most suitable beginner-friendly fish species that will do well in a 15-gallon fish tank.
How many fish can you keep in a 15-gallon fish tank?
The general rule of thumb for fishkeeping is that one inch of fish requires one gallon of water.
That sounds pretty straightforward, but there are a few considerations to be made when setting up a community tank:
- The fish’s adult size – will a small, juvenile fish outgrow the tank?
- Temperament – peaceful fish are best for a community tank
- Water parameters – all the fish, need to share the same requirements for water pH
- Temperature – all the fish must share the same water temperature requirements
- Social behavior – some fish need to live in schools, whereas others are solitary
Now, let’s check out some peaceful community fish species that would do well in a 15-gallon tank. Always research each species temperament and requirements thoroughly before you buy!
The Platy is an attractive, lively fish that comes in a range of colors, including orange, red, silver, and multicolored. Platies are livebearers, and if you choose a mixture of males and females, you’re sure to find babies swimming around your tank pretty quickly!
The Swordtail is a beautiful community fish that looks similar to the Platy. Males have a distinctive sword-shaped tail fin, hence their name.
Swordtails come in a wide range of colors, including silver, orange, red, black, and multicolored variations. These fish are livebearers and will breed readily in an aquarium setting. When choosing this species, you should always go for two females per male to reduce stress on the females as the males can become extremely attentive when spawning.
Mollies are lively, attractive fishes that make a great addition to community tanks. These appealing fish come in many colors, including black, orange, red, marbled, and silver, and there are several different varieties, including Balloon mollies. Mollies are livebearers, and they spawn prolifically!
As with Swordtails and Platies, always have more females than males to reduce stress levels in the tank, and be ready to find a swarm of babies in your tank on a regular basis!
#4 Corydoras catfish
Corydoras catfish are a community tank favorite. These cute little catfish live at the bottom of the tank, foraging through the substrate for uneaten food and scraps, occasionally darting up to the surface to take a gulp of air.
Corys come in several varieties and colors, and they are shoaling fish that need to be kept in a group of four or more. These fish are extremely hardy and easy to keep, making them perfect for a beginner’s tank.
#5 Dwarf Gourami
Gouramis come in many shapes and sizes, but the Dwarf gourami is suitable for life as a member of a community fish tank.
Male Dwarf gouramis are incredibly beautiful, elegant fish that come in several color morphs, including powder blue, red/blue, and turquoise with vertical red stripes. These are shoaling fish that are happiest in a small group of four or more.
These small, peaceful fish like a heavily planted tank with plenty of hiding places.
#7 Zebra Danio
The Zebra Danio is a stripy fish that ‘s easy to look after and perfect for beginner fish tanks. These small fishes are super-active and are happiest when kept in a school of at least five or six individuals.
These are hardy little fish that need plenty of open water swimming space to accommodate their lively temperament.
#8 Ghost shrimp
You don’t need to keep only fish in your aquarium! Some invertebrates such as shrimp can make a helpful addition to the community, as they will readily eat algae and clean up bits of uneaten food and general detritus too.
Ghost shrimp are entertaining to watch, easy to care for and get along fine with most small fish species. Ghosts are happiest when kept in a small group, and they will reproduce if given the right conditions.
#9 Cherry shrimp
Cherry shrimp also make a great addition to your tank’s clean-up crew, and they add a splash of color too.
These brightly colored, tiny crustaceans spend much of their time exploring the plants and substrate, looking for algae or scraps of food to forage. Although these little guys are peaceful, they can make a meal for larger fish, so choose your community members with care if you’re planning on adding Cherry shrimp to the mix.
Guppy fish are perhaps the most popular community tank fish on the planet! With their bright colors, flashy tails, and busy characters, they certainly do create a wonderful display.
Guppies breed constantly, and you can have great fun crossbreeding different strains and colors to create your very own unique hybrids of these adorable little fish.
A 15-gallon fish tank is the ideal size setup for a beginner aquarist who’s looking for a manageable setup with which to begin their hobby, and the tanks we’ve featured in this article are all good quality products that may provide you with just what you need to get started.
When choosing fish for your tank, always select peaceful species that are known to get along, and if you’re unsure, ask the assistant in your local fish store for advice and guidance.