“Recycled Materials in Aquaponics – Dos and Don’ts.”

Starting an aquaponics garden can seem overwhelming at first, particularly when cost is concerned. After all, not only will a variety of plumbing supplies be needed, but you’ll also need tanks, gravel, heaters, monitoring devices for acidity, and more. Using recycled materials can drastically reduce the cost for beginners and novices alike, and it can also help you create a more customized system. However, because this system is used to grow food and sustain the life of healthy animals, certain considerations should be made when choosing the appropriate materials for your setup. Take a look at the list below, which outlines the do’s and don’ts for using recycled materials in your Aquaponics Setup.

Do:

• Insure that your containers are sturdy and waterproof. This may seem obvious, but it’s important that any spaces around plumbing fittings are properly sealed so that no water escapes. In addition, you’ll need to insure that the container you’ve chosen can support the weight of the water and gravel once it’s filled to the desirable level. Some containers are waterproof, but will only support a low amount of weight before giving away. Be sure to test your containers with water and gravel before setup to avoid costly and disappointing messes and chaos.
• Use items that are food safe. As Sylvia Bernstein states in her book, “Aquaponic Gardening,” your system will be a home for many living things, some of which later will be eaten. “They all depend on you for providing a safe, non-toxic environment. This becomes especially important if you are re-purposing storage containers to create your aquaponics system.” Even items such as gravel will need to be researched to insure that they are non-toxic, as most standard aquarium gravel is not safe for aquaponics.
• Consider what was previously housed in the containers you use. If chemicals were stored in a plastic container, for example, the plastic has likely absorbed some of the chemicals and could release them back into the water of your system.
• Be cautious of already recycled materials, particularly plastics. While recycled plastics are earth friendly, according to Bernstein, “it also exposes you to a loss of control over the exact composition of your container and can’t be guaranteed safe for your plants, fish, bacteria and worms.”
• Consider the color of your container. When recycling containers, it’s a safe bet to assume that anything black once held chemicals, and is probably best to avoid. The dark color can also make cleaning a challenge, as well as attracting more heat when placed outdoors. However, white containers attract more algae, so you’ll need to check these more often to make sure all of your levels stay well controlled. Most people prefer blue for its ease of cleaning.
• Use old bathtubs. In fact, there is an entire guide by Murray Hallam called, “Bathtub Aquaponics,” which outlines each step of creating a custom aquaponics system made of an old bathtub. These containers are food safe, large, sturdy and often free.

Don’t:

• Do not use metal containers, even galvanized metal, for either the grow bed or the fish tank. The only exception to this rule is if the tanks or grow bed are lined with acceptable materials. Because metal can quickly corrode, your tank’s pH balance can be thrown into a bad cycle from the release of these chemicals into your water. In addition, copper and zinc should be avoided completely, as these chemicals are dangerous to fish.
• Do not use uncoated concrete. You may use uncoated concrete only if there is a food safe barrier between the concrete and the water, as the exposed concrete can alter the pH balance of your system.
• Do not use plastic containers without support, as the weight of the water and gravel will eventually weaken the plastic and cause leaks or breaks.
• Do not use glass containers, such as fish aquariums, outdoors. The thin, clear glass allows excessive heat to come into the container during the day, and escape it during the night. The temperature fluctuations, combined with the fragility of this glass in wind, rain, etc., make it a very poor choice for outdoor use. Indoor, however, aquariums work quite perfectly.
• Do not use containers with sharp edges inside, as these can affect both your fish and your plants. Sharp edges can cause a plant’s root to split, a swimming fish to get injured, and even personal injuries while you’re working on your system. Insuring all lines are smooth will help plants grow healthier, and fish to be happier and healthier.
• Do not forget to calculate the size of your grow beds based on your tank. For example, an unused swimming pool may seem ideal to grow your fish, but the average swimming pool contains approximately 20,000 gallons water. Ideally, you would want to stock this amount of water with about 4,000 pounds of fish! In addition, to determine the size of your grow bed, you should divide the gallons of water by 7.5 to determine the cubic feet needed. This means a 20,000 gallon swimming pool would need 2,667 cubic feet of growing space! This is much too large for any hobbyist, especially those just beginning.

Overall, using recycled materials is a great, affordable way to get started on your own custom Aquaponics system. Though some caution should be taken to avoid chemicals leaking into your water and food supply, some quick research can alleviate many of your concerns. The beauty in aquaponics is that it is a self-sustainable ecosystem that is both earth friendly and effective. Adding recycled materials to your plan is just one way to go a little greener.