10 Of The Best Fish For 15 Gallon Tanks!

Celestial Pearl Danios, Neon Tetras, Guppies, Honey Gourami, and Pygmy Corydoras are all great fish for 15 gallon tanks.

With 15 gallon tanks becoming increasingly popular, I wanted to publish this article on the best fish for 15 gallon tanks.

I hope I can help you find the perfect fish for your tank so I have a great range to choose from.

Celestial Pearl Danios

Celestial Pearl Danios
Celestial Pearl Danios

Celestial Pearl Danios are one of the best fish to keep in 15 gallon tanks as they are easy to keep, have bright colors, and display interesting behaviors.

These can work well in community tanks but often display their best colors and behaviors when kept in a species-specific tank.

Most cycled 15 gallon long tanks with a decent filter should easily support 15-30 Celestial Pearl Danios as these guys only max out at 0.7 inches (1.78cm).

Male Celestial Pearl Danios have the brighter colors but you may want to stock your tank at a ratio of 1 male per 2 females to minimize aggression.

The two main downsides of Celestial Pearl Danios are their higher-than-average price tag and the fact that even with a higher price, people still buy them in droves making them difficult to find in some areas.

Neon Tetras

Neon Tetras
Neon Tetras

Neon Tetras are one of the most popular fish in the hobby and can work well in most 15 gallon tanks.

My neon tetras chase each other from time to time to maintain their hierarchy but they never act aggressively to their tank mates.

This makes them a great fish for community tanks and species-specific tanks but I like to keep mine in community tanks with other featured fish on this list.

Neon tetras will usually max out at around 1.2 inches (3cm) so you can keep 10-20 of them in a standard 15-gallon-long aquarium.

The main downside with Neon Tetras is the number of potential health issues the fish can have due to inbreeding to meet their demand in the hobby.

Reputable breeders can be found online via sites like eBay and apps like Band to increase the chances of getting healthy fish.

Guppies

Guppies
Guppies

Guppies are beautiful fish and can thrive in 15 gallon tanks making them a great option for beginners and experienced fish keepers.

Like most other fish in this article, guppies can be kept in species-specific or community tanks with minimal issues.

There are two main types of species-specific guppy tanks. A male-only tank and a breeding tank with both serving different purposes.

Male-only guppy tanks keep male guppies to maximize the amount of color in your fish and reduce the chance of over-population in your aquarium.

Breeding tanks are specifically set up to breed as many guppies as possible but due to their rapid breeding rate, I don’t recommend these for beginners.

A male-only guppy tank can usually house 10-15 male guppies without issue with breeding tanks being more difficult to stock.

Many people will keep one male with 2-5 female guppies but the baby guppies (fry) need to be moved to a dedicated grow-out tank to prevent them from breeding with their parents and causing genetic issues.

The main downside of guppies is the various health issues they can have due to inbreeding to promote specific guppy types.

Honey Gourami

Honey Gourami
Honey Gourami

Honey Gourami are one of the most underrated fish in the hobby as they are cheap, easy to keep, look great, and have interesting behaviors.

They are one of my top 3 fish in the hobby and are perfect for beginners looking to stock a 15 gallon tank.

Honey Gourami come from India and have evolved to deal with huge fluctuations in their water parameters due to the monsoon helping you overcome some common mistakes beginners make.

Unlike some of the larger types of gourami, Honey Gourami are peaceful fish and work well in community tank setups but can be kept in species-specific tanks too.

A species-specific 15 gallon Honey Gourami tank can house 5-7 fish without issue but I recommend keeping 2 males and 3-5 females if possible.

The only real downside of Honey Gourami is the lack of color as they are all predominantly yellow but their interesting behaviors help overcome this and make them interesting to watch.

Pygmy Corydoras

Pygmy Corydoras
Pygmy Corydoras

Pygmy Corydoras have seen a huge spike in their popularity and their small size makes them a great fish for 15 gallon tanks.

These tiny, cute corydoras can be kept in community tanks or species-specific tanks but I would lean more towards keeping them in a community tank if possible.

Unlike other corydoras, Pygmy Coryies will use the middle of the water column but this leaves a lot of the tank unoccupied.

Pairing them with some type of rasbora that will usually stay towards the top of the tank can be a quick and easy way to overcome this.

Downsides of Pygmy Corydoras include their lack of color, a higher price tag, and being difficult to find in some areas.

Endler’s Livebearers

Endler's Livebearers
Endler’s Livebearers

Endler’s Livebearers can be a great choice for 15 gallon tanks working well in both community and species-specific tank setups.

Endler’s Livebearers are cousins to guppies and come in a range of colors but tend to have fewer health issues.

This makes them a great option for beginners looking for a healthy, easy-to-keep fish.

With the fish coming in a wide range of colors, I would lean more toward an all-male-specific Endler’s Livebearers tank.

Male Endler’s Livebearers max out at around one inch (2.5cm) so you can keep 10-25 of them in most 15 gallon tanks.

Just like guppies, Endler’s breed quickly so I don’t recommend breeding setups for beginners.

They can also crossbreed with guppies so keep this in mind when planning a community tank with them.

Ember Tetras

Ember Tetras
Ember Tetras

The bright color of Ember Tetras makes them a big hit for planted 15 gallon tanks as their red and orange hues contrast well with plants.

Ember tetras can be a great addition to community tanks but I lean towards keeping them in a species-specific heavily planted 15 gallon tank to maximize the effect of their color.

These are one of the smaller tetra species and usually max out at around 0.8 inches (2cm) so you can keep 20-30 of them in a heavily planted 15 gallon long tank.

You don’t have to worry about keeping a strict male-to-female ratio either as the male Ember Tetras will form their own hierarchy in the tank for breeding rights.

The only real downsides of these fish are their higher price tag and availability as they can be difficult to find in some areas.

White Cloud Mountain Minnows

White Cloud Mountain Minnows
White Cloud Mountain Minnows

White Cloud Mountain Minnows are another underrated beginner fish for 15 gallon tanks that are hardy and easy to keep.

Again, these guys work well in community or species-specific tanks and work well with a huge range of different tank mates.

Depending on the exact setup of your 15 gallon tank, you can keep 6-20 White Cloud Mountain Minnows in a 15 gallon tank with a suitable filter.

These fish are cheap and easy to find in most areas making them a great option for people new to the hobby.

One potential downside is their lack of color but they make a solid fish for most beginners.

Neocaridina Davidi

Neocaridina Davidi
Neocaridina Davidi

A Neocaridina shrimp tank can be a great option for a 15 gallon tank and the wide range of color options ensures there’s something for everyone.

I am a huge fan of shrimp keeping and one of the main advantages of Neocaridina shrimp is that they can work well in everything from a small 1 gallon tank and up.

Optimal breeding tanks are usually within the 5-40 gallon range with a 15 gallon tank being an excellent tank size for someone’s first shrimp breeding setup.

Other than Guppies and Endler’s Livebearers, Neocaridina shrimp are one of the better options for anyone looking to use their tank for breeding to earn a small side income too.

My article on different Neocaridina colors goes into the various options in more detail and my article on setting up a shrimp breeding tank should be helpful too.

Betta Fish

Betta Fish
Betta Fish

Betta fish can be a risky addition to a 15 gallon tank but in certain setups, they can work well.

I usually try to keep my betta fish in 5-10 gallon tanks with the betta being the only fish in their tank to prevent problems with aggression.

Some people are lucky and get a betta fish that can work in a community tank but I wouldn’t recommend trying this unless you have a backup tank for your betta.

When keeping a betta fish in a 15-gallon tank, I lean more toward a heavily planted paludarium or riparium setup.

This reduces the “wasted space” in the tank and lets you