Aquaponics fish

Fish are absolutely essential in any succesful system design. Many people use Tilapia as their choice for aquaponics fish. But what fish can be used other than Tilapia? And how do aquaponics installations in different parts of the world affect the types of fish used? This fish for aquaponics resources page answers these questions.

One of the critical choices that must be made, and must be made right, is the choice of fish for aquaponics. Many different types of aquaponics fish can be successfully used, but not all will be able to survive in your particular climate, and some are more forgiving than others for fluctuating levels of nutrients in the water. If something goes off for a period of time (and it will, whether it is pH, ammonia levels, water temperture, oxygen levels, or something else), you don't want your fish to have died as your indicator.

Good choice for fish for aquaponics

Personally, I'd not consider including anything other than the species in this list. I'll update this aquaponics resources page if I learn of information that changes my mind, so if I am wrong - let me know!
  • Tilapia. This is the favorite for most aquaponic enthousiasts. The fish is easy to get (year round), is happy in a tank, stays healthy in the system and has a good growth speed. Oh, and it tastes nice.
  • Catfish. This is probably a number 2 favorite for raising in aquaculture. As catfish generally like to swim near the bottom of a tank, the tank is likely to be "more crowded" at the bottom than when using Tilapia.

The reasonable aquaponics fish choice list

  • Goldfish. Most people know the little orange creatures that are often kept in indoor aquarium. They are nice to look at and are happy in a tank. If you like to look at these fish, then including a (beautiful) tank in your system design could be the way to go. But most people prefer to be able to eat the aquatic produce as "aquaponic harvest". The goldfish don't meet this criteria.
  • Koi. As with the goldfish, don't include these aquatic animals in your design if you want to be able to "harvest and eat" them. Koi are not considered edible. But if you have them anyway, like the way they look, and would like to keep them, then they can be included in the system.

The bad choice aquaponics fish list

I considered naming this section the "don't get these types of fish for aquaponics systems". You could use almost any creature that lives in the water as part of the setup, but some are more difficult to feed, more difficult to keep healthy, or are slow to grow or not edible.
  • Salmon. Athough great to eat, raising salmon in your aquaponic system is far from ideal. Salmon are carnivorous, which means that they must be fed with food produced from other (aquaponics) fish that is often caught in a non-sustainable fashion. Farming salmon takes much more food intake than they produce.
  • Trout. Trout are closely related to salmon. They also feed on other fish, which means feeding them is much more time consuming and expensive.
  • Carp. As with trout and salmon, carp feed on other fish. So I refer to the two bullet points above for information why I think carp is a poor choice for including in your design.

Combining different types

It is certainly possible to combine different types of fish in one system. Perhaps I will dedicate a aquaponics resources page to this subject. For now my thoughts are: The two most obvious methods for keeping multiple types in the same system are two tanks (or one large tank with a barrier between two sections), or simply keeping multiple types in one and the same tank. Keeping them in different tanks will be useful when one type tends to want to eat the other type, when feeding requires seperation or when they require a different water temperature. Otherwise, keeping them in the same tank will make the most sense. But remember that it will not allow water quality characteristics to differ (pH, ammonia levels, etc), as the water will be mixed between the tanks when it travels through the plant beds. Even if you try to have the water return to the tank it came from (high complexity), you will never be able to keep it completely seperate.

When to eat the fish

Fish can be harvested when they reach plate size. Generally, fish will be harvested at about 1 year. There is no need to harvest them all at the same time, just take what you need from the system and leave the rest in the tank. Harvest the largest fish first.

Other useful info

This is my collection for relevant information that I don't want to store on this aquaponics resources page (to keep it concise) and I also don't want to include on the species subpages.
  • Remember, fish need oxygen! If the aerator stops working (ie power outage) the aquaponics fish can die in 30 minutes. You can buy battery operated aerators, or use uninterrupted power supplies as an additional safeguard. People also use (large) compressors as an aeration source - they store a lot of compressed air and depending on the size can aerate a tank for many hours after a power failure.
  • Keeping fish for aquaponics in tanks. There are a number of general rules that apply equally to all types of our aquatic friends. I have created a special page that captures this information, which you can find in the link section to the right.
  • Energy efficiency. I'll be focussing on building a highly energy efficient design, and energy efficiency in keeping tank water temperature in the preferred ranges will be a major item in the aquaponics resources pages. I'll be including solar water heating using a buffered tank design, and water-water heat exchangers for feeding the water from the tanks to the plant beds. Custom computer controlled circuits will be optimized for energy efficiency, and I expect to add an Arduino section to the aquaponics resources pages, as an Arduino is the best method I know of to easily automate the process based on multiple sensory inputs.