Aquaponic Economics ~ Fish Selection

Aquaponic Economics ~ Fish Selection

In my last post, I discussed some options for raising fish in a cold climate.  This post discusses which fish to raise, based on the economics.  

The following table shows my best estimates for the amount of time it takes to grow out different varieties of fish in the different seasons, the costs of purchasing stock from my local hatcheries, and the value of those fish when grown.  Note that the value listed here is the value to me.  You could sell perch for more than $4 per pound, especially during Lent in Wisconsin, but I’m not willing to pay more than $4 for large quantities of it.   You should do your own math based on your own hatchery prices and what you’re wiling to pay for fish.  For instance, if I lived in Colorado I might raise hybrid bass.  However, I can’t get them here.

Aquaponic Fish Growth Rates

The table assumes the following growing conditions. 

  • Summer water temperature of 78°F
  • Winter water temperature of 50°F
  • Fillets make up about half the weight of a full grown fish.
  • You increase the temperature such that tilapia survive the winter, though without growing.  Alternately, you could move them indoors.
  • You cool your water for the 4-6″ trout in the summer.
  • Does not include construction, feed, energy, automobile, or other costs.

At these temperatures, I presumed little growth for catfish, bass, and perch in the winter.  If your seasonal water temperatures differ from these, your results may differ, especially with regard to bass and perch which can grow somewhat faster at temperatures above 60°F.

As shown here, local hatcheries give me the option to raise a wide variety of types of fish in my area.  Depending on the size I buy from the hatchery, I can grow out some of them in a single season while others take three seasons (including a non-growing season in-between). 

Given the amount I’m willing to pay for large quantities of full grown fish, the most valuable fish to grow are rainbow trout and catfish.  In my system, I can do this since I have multiple fish tanks and can keep the catfish alive and separate from trout over winter, growing out them out primarily in summer.  If you only have one tank such as in the Zero to Hero system, trout in winter and tilapia in summer works better.   

Depending on your culinary tastes, the water temperatures you choose to maintain (based on the cost to heat/cool), etc… perch might make more sense for you from an economic perspective.

Another concern with regard to larger fish (like 8-10” trout) is the need for in-travel aeration of you move fish more than 150 miles.

So there you have it.  An economic analysis of fish selection for a cold climate.  

You Respond

How do your hatchery prices, temperatures, and the value you give to fish change the economics for you?