DSC_0527Simply put, it is the combining of two sciences Aqua-culture (the growing of fish or shell fish in a controlled environment) and Hydro-ponics (growing plants in water). In this unique symbiotic method the “dirty” fish water rich in nutrients and fish waste is used in the hydroponic beds where the plant roots take up the nutrition they need and in so doing, help filter the water. The now “clean” water is pumped back to the fish tanks. While this over-simplification helps define the term for better understanding, aquaponics is by no means simple. It is a careful and delicate balance of fish to plant ratios, fish feed and waste to bacteria colonization, temperature, pH and dissolved oxygen controls, all working together in a micro eco-system.buttercrunch lettuce
The big advantage over hydroponics is that in the latter, chemicals constantly have to be added to the water, toxins then buildup and the water has to be regularly changed. The now toxic water is normally dumped where it will event
ually wind up back in our water table or streams and rivers. In aquaponics the water is recycled and only a small amount of fresh water is added occasionally to replace that which is lost to evaporation.

What are the “Pros” of aquaponics and why is it becoming so popular?

  • Because it is a recirculating system, it uses up to 90% less water than conventional farming methods, and in drought stricken areas or where water is scarce, this is paramount!
  • With the combination of quicker plant growth and multiple crops /year it can easily produce 800% more vegetables and leafy greens in the same amount of time and space! (At the University of the Virgin Islands they have repeatedly produced 10,000 pounds of veggies and 12,000 pounds of fish annually while recycling the same water on 1/8 acre of land!)
  • Energy requirements are 75% less than traditional farming methods!
  • Labor is less than half of that required by almost all other food production methods by saving time in all stages of production.
  • They are free from chemical fertilizers, pesticides, herbicides, fungicides and other toxic chemicals!
  • Aquaponic size versatility can range from desk top systems to “barrel-ponics” to large scale commercial farms!
  • Aquaponics has zero environmental impact, with a small footprint and high density production.
  • From a single input of fish-food, two crops are realized—fish and produce.
  • It can operate indoors or out, enabling old buildings, warehouses or “undesirable” land to be used to produce fresh fish, organic vegetables, fruit and more!


Here at Caledonia Farms we chose to raise a mixture of two different kinds of fish in our aquaponic tanks: Koi (cold water tolerant but not good for food) and Tilapia (good food choice but tropical temps only). By having two different varieties we decrease the risk of loosing all the fish should there be an accidental and sudden water temperature drop, or aquatic disease, or some other imbalance.

Tilapia is a favorite in the US for aquaponic systems for many reasons:

  • Omnivorous and can eat a vegetable or cereal-based dietDSC_8744 (1)
  • Ease of reproduction and don’t eat their young
  • Excellent tolerance of high stocking density
  • Rapid growth
  • Contain especially high ratios of omega-6 to omega-3 fatty acids
  • Excellent market and frankly … taste great!

The vegetables we are growing in the aquaponic system are cherry sweet tomatoes, swiss and rainbow chard, several varieties of lettuce, wasabi mustard greens, ong choi and pak choi. One 4’x8’ section will be dedicated to a variety of herbs and microgreens.