…if you can survive the winter.
In many parts of the world, the climate provides a short growing season for our highly perishable crops like lettuce, kale, and herbs. Combine this limitation, our growing population, and the need to preserve our precious water resources, and it’s clear we (the people of this world) will require new ways to produce our food sustainable, responsibly, and let’s not forget… affordable.
The wonderful news is aquaponics is a viable solution to that problem, and yes, it IS a problem in our world! Aquaponics combines the science of raising fish (aquaculture) with the growing of vegetables in water (hydroponics) as a symbiotic relationship that provides clean water for the fish and organic nutrients for the plants. It offers the ability for all who are willing, to provide fresh and organically grown fish and vegetables to those in need of nutrition. As amazing and simplistic as this symbiotic relationship is, it also comes with a learning curve that can at times be challenging. Surviving winter is one example…
Aquaponics will thrive with just the right amount of humidity, a balance of warmth in both water and outdoor temperatures, good light, and with a consistent dose of nutrients. Once a system is established or what the farmers call “balanced” with its perfect pH for both plants and fish, it will easily sustain itself and remain simple to maintain throughout a typical summer provided those four requirements are met consistently. But winter poses new challenges.
With winter, we have colder temperatures and less light each day. Colder outdoor temperatures and less light trigger slower plant growth. Slower growing plants take up less nutrients. Less nutrients being filtered out of the water, leave water less amiable to the fish, as does the colder water temperature. Less amiable water for the fish promotes fish disease and possibly death to fish and ultimately the plants… NOT conducive to sustainability.
So what is an Aquaponic Farmer to do? Winterize of course! This is a first in a series of articles to address small steps that CAN be taken to help stave off the “impact” of winter on your aquaponic system.
Goal #1 is to maintain the warmth as much as possible without doubling your utility bill. Many aquaponic farmers are raising Tilapia. Tilapia are native to Egypt and love to be warm. Some varieties can tolerate temperatures down to 65, but typically they want their tanks in the 68 to 80 degree range in order to live entirely healthy and happy. Average size Tilapia tanks range from 110 gallons to 300 gallons and to maintain those temperatures will require a 500 to 750 watt tank heater running 24/7. That gets very expensive. Here are two quick DIY steps for maintaining the temperature in your fish tanks, without the need for a conventional tank heater.
1. Insulate your tanks; material dependent on your climate. Central California for example can be done simply with bubble wrap; colder climates require heavier insulating material. Wrap tanks and cover tops for best results and secure with duct tape, that’s it! Make double or triple wraps for better insulation. The better the tank is insulated, the better it will maintain its temperature.
2. Heat your tanks with a solar water heater! How? There are many varieties… the easiest and most frugal is to purchase about 100 to 150 of 3/4 (fish safe) black hose. Coil it onto a flat surface which has been painted black. Anything flat will work; a pallet, a sheet of plywood, etc. Leave enough remaining hose on both ends that will be able to reach your tank from where you will place it in the sun. Secure the coiled hose to your flat surface…can be done with zip ties, duct tape, thin tack strips, or anything that will securely hold the coiled hose flat to the surface without puncturing it. Cover the coiled hose with a clear sheet or two of plastic and then secure. Once secure, lean the attached coiled hose against a post, a building, the fence, or on a roof where it has optimum exposure to the sun! All you need now is a timer, a couple of hose fittings, and a pump. Connect your pump to one end of the coiled hose and place both ends of the hose in your fish tank. Plug your pump into a timer, which will then turn it on at the first sun exposure and off as soon as the sun no longer shines on your solar heater. Water will be pumped from your fish tank, through the coiled hose, and back to the tank. Warm days will provide an abundance of heat. Carefully monitor your tanks and adjust accordingly. This method will provide the needed temperatures nearly every winter day that the sun shines. In most places, you can avoid the conventional tank heater for the majority of your winter days and save a TON of money!