School's In!

Everyone wants a school of fish for their aquarium, and with good reason. A vibrant school of fish swimming in unison is a mesmerizing sight, adding dynamic activity, movement and depth to any freshwater aquarium. Beyond aesthetics, schooling fish often feel more secure in groups, displaying more natural behaviors and reducing stress. Schooling fish also have a “dither” effect. The activity of these fish out in the open acts as a sign to other, more reclusive fish that it is safe to come out and look around, and this phenomenon as resulted in the phrase, “dither fish.”

In the wild, schooling is a behavior that helps protects individual fish from predation. More fish means more eyes to see threats. Beyond this, schools react in unpredictable ways and predators can be confounded because the individual fish will go in too many different directions. Even though these threats usually don't exist in the home aquarium they'll still school. You don't undo hundreds, maybe thousands of years of generation after generation conditioning in a couple years of aquarium life. To this point, the vast majority of the schooling fish you'll see available in your Local Fish Store have been aquacultured for decades, and they still school in your tank.

Frequently the fish you choose to school in your specific aquarium is dependent on how big your tank is. It's hard to say that you need just tetras in a small tank, because some Rasboras like Chilis are smaller than Neon Tetras, while some Tetras like Congos are sized more like Danios. Sometimes you're choosing for a specific look or trying to mimic a specific location. Other times, you're looking for something that just works in the same type of display, be it for water chemistry, or flow. The point here is do go about the business of stocking your tank with some forethought and give each species you want to mix a thorough investigation. We've got species profiles for dozens of fish on this website, and the internet abounds with hundreds if not thousands more.

One of the biggest factors in getting your fish to school in the home display is having enough of them. You need enough fish for them to actually make a school and in the end, more is always better if you have enough space and adequate filtration. Frequently, species can be mixed together and they'll often school. To this end, when most people think about schooling fish in the home aquarium, they think Tetra, but we think Tetras. Why have one species when you can have a few?

Tetras are great because you can have a large number of the smaller ones in a relatively little tank. They're incredibly colorful and active and school well in the home display. The vast majority of them have been aquacultured for decades and are well accustomed the conditions in most home aquariums. In a 20-gallon tank, you could have more than a dozen of them and if you want them to school, that's our minimum suggestion. Neon Tetras (Paracheirodon innesi) are probably the most famous and among the most brilliantly colored. Cardinal Tetras (Paracheirodon axelrodi) are very similarly colored and sized, but their red stripe is more pronounced. Rummy Nose Tetras (Hemigrammus rhodostomus) got their name from their red noses (often attributed to people who drink too much rum), but they also have slender silvery bodies and black and white striped tails. They are a staff favorite but need excellent water quality to maintain peak coloration. Ember Tetras ( Hyphessobryon amandae) are also super popular for their soft orange glow making them a great contrast to the other common Tetras. All of these, and dozens of other Tetra species can be mixed and matched, just try to have at least seven of each species, and a minimum of 14 overall if you're mixing. A better number would be 21 plus, if you have the room. All the tetras look natural in a wide variety of tanks but are especially great in planted tanks and look brilliant in Blackwater / and tea-stained displays as well. Most tetras are “mid-level” fish meaning they stay just about in the middle of the tank, most of the time.

Rasboras are another great group of schooling fish for the home aquarist. The smallest of them will be as small or smaller than Neon Tetras, and the largest of them will be more in line with Congo Tetras. They'll generally stick more to the top of the water column, but there's definitely some overlap with them and Tetras for where they like to live. Fish from these two groups can usually be kept together, but they'll form schools of their own, with Rasboras separate from the Tetra schools, which makes for an amazing display. The Rasboras also make up a gorgeous group, suitable for a wide range of aquariums. The most popular are arguably the Harlequin Rasboras (Trigonostigma heteromorpha), recognized by their distinct black triangle(ish) marking and translucent red-orange tails. They're peaceful and hardy and make great fish for beginners and experts alike. Chili Rasboras (Bororas briggitae) are among the smallest of this group and sport a brilliant red coloration. They're perfect for very small aquariums and their colors really pop in densely planted displays. They're super peaceful and active but can end up as meals in tanks that have big enough predators. Another tiny, gorgeous and super popular fish in this group is the Galaxy Rasboras (Celestichthys margaritatus). These are absolutely stunning little fish, with white or gold spots over a dark blue body. They're very small, peaceful and shy. Excellent for Nano tanks or displays with other very peaceful fish.

On average, the group of schooling fish called Barbs are slightly bigger (on average) than the first two groups. They school slightly less tightly than either Tetras or Rasboras but will still bring that schooling vibe that you're looking for, especially in slightly larger displays. They're very hardy, easy to feed and mostly get along well with other fish. The Tiger Barb (Puntius tetrazona) creates a beautiful school, and their vertical barring enhances this look. There's a good argument that they are the most common, if not most popular of the Barbs. This specific barb has a well-deserved reputation as a fin nipper, especially when kept in groups that are too small. We suggest keeping a bare minimum of six of them, which would require a 20-gallon tank. More would always be better, and they can be mixed with other species of barbs. Cherry Barbs (Puntius titteya) bring some star power with their lustrous red coloration, beautiful shape and high activity level. They are especially gorgeous when spawning. For those of you looking for a much larger schooler for large tanks, the Rosy Barb (Pethia conchonius) can get up to almost six inches long. The males sport a goldfishesque red-orange coloration with shimmering golden edges to their scales, while the females are silverier, but often also get the golden edge scallops. They are a very underrated fish.

If you're looking for something that wants a little faster water, maybe think about Danios. Danios are super active, current loving fish, but they can deal with a huge range of aquarium conditions. Zebra Danios have stripes like their namesakes and can deal with quite a bit of current in a display aquarium. They can get up to about five inches long, so make sure you have enough space for a group of them. We'd suggest no less than seven, and you'd need at least 40 gallons of water to make that work. Like all schooling fish, more is better. Another super popular fish in this group is the Pearl Danio, these fish have white spots over blue backs and red bellies. If you've ever thought you wanted to keep a brook trout or arctic char in an aquarium, this is the closest to that look you'll get without going crazy with current and chillers and a massive tank! They're very peaceful and stay quite small (less than two inches or so). They can be blended with other small schoolers.

Lastly, the one place people don't usually think about schooling fish is on the bottom. Here at Aquatropic, we're not sure most people would call them schooling, but Corydoras live in really structured groups that function like a school for the most part. They're endlessly engaging with each other and are one of the aquarium hobby's most fun fish to have. There is an opportunity here for someone to have a Rasbora school, a Tetra school and a congregation of Corys as well and have three super active groups of fish in all three levels of the aquarium! Go forth and make it so! This isn't an end-all list of every freshwater schooling fish out there, but it should give you some ideas about some different groups and perhaps some interesting species to try in your different displays. Nothing makes a community tank pop like a group of dither fish, so start thinking about how to incorporate a school in your display today!