The Best Fish for Aquaponics
What are the best fish for aquaponics? The best fish for aquaponics are freshwater fish that prefer warm or mild temperatures. Trout, Tilapia, Catfish, Bass (including Largemouth Bass), Barramundi, and Perch are popular choices.
What Makes a Type of Fish the Best for Aquaponics?
There are some really basic features that fish need to possess to do well in an aquaponic system.
First, they absolutely, unequivocally have to be freshwater fish species in aquaponics.
Marine species (meaning fish that live in saltwater) cannot thrive in aquaponics because the amount of salt they require in the water would quickly kill the plants growing above.
Next, the temperature the fish can tolerate is important.
Many freshwater fish can handle a range, and you’ll need to consider the climate and water temperature in your aquaponic system.
If you have an outdoor aquaponic system, pay good attention to both the highest and lowest temperatures the weather will reach in your area.
If you’re doing aquaponics indoors, just be conscious of the ambient temperature in your growing area, and invest in water heaters if needed.
The best fish to grow will have compatible temperature tolerances with your plants.
Generally speaking, fish that can handle a temperature range of 60 to 80 degrees Fahrenheit are best in aquaponics.
The last thing to look at is really the nature of the fish.
That means temperament (are they aggressive, docile, prone to attacking other fish), hardiness, and preferred tank capacity.
A fish that can take a wider range of conditions is going to do better in unexpected changes (for instance, an unseasonal heat wave), and is likely to reproduce better.
What kinds of fish can you grow together in aquaponics?
The best fish for an aquaponic system range from herbivore to omnivore to carnivore, and each species has a different temperament, needs, and levels of aggression.
That doesn’t mean that you won’t ever be able to pair a carnivore species with herbivores, or a more aggressive species with a more complacent one.
Some species cannot be put in a smaller tank together, but will more or less get along in a larger tank.
Likewise, an aggressive top swimming species will target a gentle top swimmer, but generally leave the bottom feeders alone.
In many fish, aggression is more linked to being territorial rather than just having an attitude problem.
Here are the top tips on choosing good fish to grow together:
Pay attention to size and gape: basically, if you have different species in the same tank, make sure that smaller fish aren’t so small as to fit into the mouth of one of your carnivorous fish.
That’s a big reason that it’s so hard to keep crayfish with other fish: they’re so small other fish automatically see them as food.
Just because different species may reach the same adult size doesn’t mean they’ll grow at the same rate.
So again, pay attention to size and growth rate so you don’t end up with fingerlings that get eaten.
Get a big enough tank.
If you cram a ton of fish into a small space, it’s not a good situation, even with the same species.
Many species that are otherwise fairly docile will eat smaller fish, especially younger fish.
If you’re breeding your fish, grade the fish by species and size and separate until they reach comparable sizes.
Here’s a chart to reference for the best freshwater aquaponic fish species:
Note: This chart indicates growth time, essentially meaning how long it will take the average fish to reach plate size. Keep in mind growth rate can change dramatically with different conditions, so try to maintain optimal ranges for your fish. Naturally, ornamental fish won’t be eaten, and have a lifespan listed instead.
More About the Best Freshwater Fish for Aquaponics
Barramundi grows quickly, and are a popular fish in cuisines worldwide.
This warm water fish also eats quickly, so water quality needs to be monitored, although the waste they produce is great for your plants.
Barramundi are certainly entertaining (and delicious), although they are a fish to try out after you have some experience.
Because of their predatory nature they need to have plenty of separate enclosures, especially until they reach about 4-6 inches.
Want to see our Top 9 fish that are best suited for aquaponics check out our article.
The main kinds of Bass grown in aquaponics are Striped, Smallmouth, and Largemouth Bass.
These fish can tolerate a wide range of temperatures, which makes them easier to care for in aquaponics.
They also can be paired with other species fairly easily despite being carnivores (common pairings include trout or catfish), although you do still need to keep fish around the same size together.
Bass are hearty and a good choice for beginners, but be patient as they take a little longer to reach popular plate size.
Bluegill are another edible, delicious species you can grow in your aquaponics system without much work.
The only time they’ll really require extra attention is when they’re breeding and have fry (which will need to be separated to avoid being cannibalized by the adults).
Aside from that, they’re quite easy to breed and grow to plate size quicker than many species.
Since they’re not a ‘tropical’ species, they can tolerate a range of temperatures and often don’t require a water heater.
Carp is by far one of the easiest fish to grow in an aquaponics system.
They grow quickly, and often don’t need a heater, even in outdoor rigs (if you plan on a few seasons).
It’s better to feed carp small amounts at once, but feed them frequently for the best growth.
They’re also easy to breed and don’t have as concerning predatory habits around smaller fish and fingerlings as other species do.
As always, Catfish are a popular plate fish, whether homegrown or self caught.
These fish are great in an aquaponic system for a few reasons: first, they’re fast growing and can get to plate size in less than 6 months.
They’re also easy to pair with other fish, since they’re peaceful and keep to themselves.
Finally, Catfish are bottom feeders that eat just about anything, and clean up detritus from the bottom, which keeps the tank clean.
Since they don’t have scales, they have to be skinned before cooking.
Goldfish are an ornamental species, and aren’t suggested for eating.
As a species that prefers cooler temperatures, they do well without a heater, and are a hardy fish.
They do well in a variety of conditions, and still produce the helpful fertilizer that will help your plants grow.
If you plan on having aquaponic Goldfish, opt for those sold as pets, and not feeders to reduce incidence of parasites.
Koi are another ornamental fish, and shouldn’t be eaten.
That said, they’re still great for enhancing your aquaponic system, and make entertaining pets.
Koi are actually a type of Japanese Carp, although their popularity has spread worldwide.
These fish are also great for beginners, since they’re highly parasite resistant, and can handle temperatures from 35 to 85 degrees.
Murray Cod are a good fish for a heavily stocked aquaponic system, and can handle stocking densities greater than most species.
They do prefer cooler water, but can handle water at up to 75 degrees. Within a year or less most Murray Cod will have grown to plate size.
These fish aren’t picky about what they eat, which also means that they’ll eat smaller fish that fit within their gape.
Perch has a few varieties that are ideal for aquaponics, namely Yellow, Silver, and Jade Perch.
These edible fish are high in Omega 3 fatty acids, which is another benefit to having them in your aquaponic system.
While Perch are primarily carnivorous, some varieties such as the Jade Perch are omnivorous.
With proper conditions and feeding you can have plate size fish within 9 to 12 months.
Perch are exceptionally hardy, and inexpensive to feed, so they are good for beginners.
Tilapia is one of the most popular plate size fish globally, although when imported they can contain chemicals or antibiotics, so many aquapons opt to grow their own.
They do like warmer temperatures, so a heater is advised if your growing area will be cool.
Tilapia are very easy to breed as long as you lower tank temperature to the 70s and provide them darkness.
They also grow faster than most species, taking only about 6 months to grow to plate size.
Trout are another popular plate size fish that grow quickly and tolerate cool temperatures well.
This species is closely related to salmon, and will eat anything from insects to mollusks.
Rainbow trout remain one of the most popular varieties, both to grow and eat.
Rainbow Trout especially need a high protein diet, with up to 40% protein being optimal.
They can grow to be large in the wild (up to 27 lbs), but are typically you will get the popular plate size within 9 months.
How can I deal with predatory fish species?
The best policy is to separate predatory species from smaller fish, and sometimes from other fish altogether. Tank dividers are widely available for purchase, and will make a huge difference.
How to prepare aquaponic fish for harvesting?
This will depend on species in some cases, although most fish need to be ‘purged’ before harvest. This means the fish go without eating for a few days to clear waste from their system.