Best Fish Species for Aquaponics:There are many different types of fish that you can use to stock your aquaponics system. Since the climate can affect the general health and ability to reproduce it is always a good idea to check with your local agriculture bureau before deciding which fish is best suited for your area.
Since different species of fish grow and spawn differently, we need to understand those differences. Ideally, we are looking for a fish that is well adapted to the local conditions, that puts on mass quickly and is hardy in a closed system with other fish of the same species.
There are also concerns with reproduction of certain species. It might mean they are slow to spawn and multiply, or not able to reproduce at all in a closed system. Certain types of fish will need to be manually restocked with minnows to maintain an adequate fish population.
We'll cover some of the most commonly used species used to stock aquaponics systems:
Tilapia is an excellent choice for an aquaponics system and have been farmed for generations in Asia. Their hardiness and growth rate translate to a high yielding fish population. Tilapia are also known to be extremely good to eat and produce a white, mild tasting fillet that is always a welcome addition to the dinner table. Tilapia is a member of the cichlids group of fish that is comprised of two to three thousand different species within the group. Cichlids include many freshwater fish commonly found in aquariums and even includes the renowned game fish called the peacock bass that is native to South America.
For our purposes, their ability to thrive in a closed system along with feeding on plant material, in lieu of other fish, make them an outstanding choice for aquaponics. Tilapia are sometimes called "water chickens". Tilapia are non-native fish outside of the tropics so you will need to prevent your tilapia from entering any natual waterways. Chances are they will out-compete native fish and have a negative impact on the native fish population. Tilapia released into the wild will reproduce with other tilapia species and produce a hybrid tilapia.
The white bass is commonly found in the south and midwest of the United States. They are good to eat (and fun to catch!) and can be a good choice for stocking your system. Where tilapia are plant eating fish, white bass are carnivorous and prey on small crustaceans and other small bait fish.
In the natural environment, a single white bass will lay as many 900,000 eggs during the spawning season. The white bass does not have a nest and don't tend to the eggs the spawning. Adult white bass simply leave the spawning sites after the eggs have been fertilized. White bass can grow up to about two pounds, but the average size for this species is about nine inches with an average weight of less than one pound. White bass are schooling fish and can be caught in great numbers in large reservoirs. It is not uncommon for a group of fishermen to catch hundreds of white bass with rod and reel in a single fishing trip.
A third favorite for stocking an aquaponics system is the crappie (pronounced crop-ee). The crappie is a favorite at the dinner table and can be cooked in a variety of ways. More importantly, similar to the tilapia, it adapts well to closed systems.
The downside of crappies (unlike other fish) is that is takes two years to mature to adulthood when they are able to spawn and reproduce. Crappies lay eggs on a nest. After the female crappie lays the eggs, the male crappie guards the nest from predators. After about ten days, the fertilized eggs hatch and the cycle repeats.
Crappies are predator fish and feed on insects and small bait fish when raised in a closed system like a fish tank. Never stock crappies with larger predator fish such as bass, walleye or catfish since the larger fish will actually prey upon crappies.