It’s called aquaponics, not to be confused with hydroponics. Have you ever seen the very cool water white towers dripping with lush green plants? You know, the ones grown without dirt, without fuss? Well this is one step above hydroponics because not only does it utilize the “fast feed” system of cultivating plants in water, it does so by adding fish poop into the mix. Huh?
Stay with me. It was an odd concept for me to grasp, too. I’m used to digging in dirt, remember? Aquaponics is actually a combination of aquaculture (raising aquatic animals such as fish) and hydroponics (cultivating plants in water). It’s the method of growing crops and fish together in a re-circulating system (think: ebb and flow) where the byproducts from the fish are filtered by the plants as vital nutrients, after which the “cleansed” water is returned to the fish.
Basically you set up a simple fish tank (shown above covered with blue blanket due to temps and the fact these fish aren’t fond of bright light), hook it up to plastic plan beds filled with special water retaining gravel and turn the power “on.” I do love EASY!
According to GrowingPower.org: “By using gravity as a transport, water is drained from the fish tank into a gravel bed. Here, beneficial bacteria break down the toxic ammonia in fish waste to Nitrite and then to Nitrogen, a key nutrient for plant development.” The key here being gravity and/or “raised beds” which equals “no bending!”
The system I observed used Hydroton for gravel. The clay is formed into pellets and fired in rotary kilns at 1200C, causing it to expand inside and become porous. Expanded clay is light in weight, will not compact, and can be cleaned & sterilized for reuse. These are inert, pH neutral and contain no nutrients. The pellets drain freely and don’t hold excessive water. They provide excellent oxygen levels around the roots. Hydroton is pH neutral and does not degrade. Interestingly enough, earthworms can live within this gravel thereby adding even more nutrients for your plants! (Will miracles never cease?) I LOVE worms!
Tilapia is a perfect fish for aquaponics because of its rapid growth, large size, and because it tastes great (in case you want to eat some of them!). This hardy fish can adapt to most any condition with the exception of water temperature. Tilapia prefer warm water – at least 75 degrees Fahrenheit. It takes about 9 months for our Tilapia to grow to a harvestable size, about 1.5 pounds but if you feed them duckweed, ground-up salad greens from your plants, they’ll get there in no time. 🙂 Tilapia will also eat algae from the side of the tank.
As water circulates through the plant beds and back out again, bacteria play an important role, ie. by removing the ammonia from the water before it heads into your plants. According to Backyard Aquaponics, “this is not a special or magical thing unique to aquaponics, filters in home aquariums as an example use the same families of bacteria to perform the necessary task of removing the ammonia in a very similar fashion.”
Now in the beginning it takes a bit of time for the bacteria to form and grow to the point where it reaches optimum performance, but gardening requires an investment. Whether it be in your time, money, your back muscles… Things don’t happen overnight when it comes to Mother Nature. But reasons to consider aquaponics? That’s easy. No bending, no weeds, faster growth, organic, healthier eating & sustainable living ~ just look at this gorgeous lettuce bed!
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