DIY Combined Aquaponics and Hydroponics Gravity-fed Food and Fish Production System

Let me tell you a little bit about a cool aquaponics and hydroponics food production system that I’ve built on a small scale several times using very simple parts and with great success. A combined aquaponics and hydroponics gravity-fed food and fish production system is just what it sounds like- you grow plants and fish together in one system. There is no dirt or soil for the plants, but instead, they are fed from the water containing fish waste that is recycled through the system. In turn, the nutrients released by the plants and the ecosystem that is created will begin to feed your fish as well as to sustain a healthy oxygenated water environment.

 

The first DIY aquaponics/ hydroponics system in production.

For the system displayed in the photos, you will need one standard aquarium pump to move the water from the bottom container or holding tank up to the very top container. The system then filters the water through the plants utilizing gravity to move through each catchment level in the system.

For plant growing medium, you can use small stones, pebbles, or the clay hydroponic growing medium. Hydroponic clay growing mediums are expensive so I usually opt to use small stones and pebbles from any standard landscape supply. Use larger stones by the drainage tubes and smaller pebbles in your planting area. Do not use any dirt or sand in your plant beds as this will clog your system and is unnecessary. The plants and pebbles will filter the water adequately and provide an ecosystem for your plants to thrive in.

In the first DIY system built, I used goldfish because they are very hearty fish and I wanted to make sure that I didn’t kill them easily. I’ve built three systems sense and I’m now using catfish because this is a fish I would like to grow and eat myself. Catfish do not require a lot of heating unless it gets to freezing temperatures so in my climate they work well. Tilapia are also a good choice if you can provide heat in the winter and trout is a great choice to grow in colder climates. You might start with goldfish to start your system, but do not grow goldfish with any of these other fish types. Goldfish waste can be toxic to other fish.

Monitor your combined aquaponics and hydroponics system closely for health. Watch for stress points like when you first add the fish and the plants are small or when the plants are large and you harvest the fish it will stress the plants. Look for signs of stressors, such as wilting or sickly plants, cloudy water, dying fish, or too much algae growing. You want some algae and bacteria and a healthy system because this is what will eventually feed your fish. When first starting your system, you will need to feed your fish, but as your system matures, the fish will begin to feed on the algae and particulates created.

Arrange your growing containers with the plants planting bed at the top then have that feed into a containment area in the middle for an overflow, and lastly at the bottom of the gravity-fed system have your fish. Consider paying a little bit more for the plastic irrigation tubing that is meant for drinking water pipes (PVC). You’ll need to slowly add water and run the system for several days without any plants and fish to make sure that your bacteria environment is starting to grow in a healthy way. Do not add any chemicals to the water for the fish, as these chemicals will be absorbed by your plants that you're adding. Also, consider light needs: install an indoor growing lamp over the plants at the top or place everything in front of a sunny window.

 

Small systems can be built without need for a pump, but water quality must be monitored even more carefully.

A combined Aquaponics and hydroponics gravity-fed food and fish growing system is really not as complicated as it seems. Once you start building your own DIY system and see how the fish and plants feed each other, you’ll be hooked too. The best part is when you begin harvesting your fresh fish and vegetables right from your DIY system. Happy growing!

#amberclee