Regardless of the structure, there are certain things all aquaponics systems need. Consider this the “outline” of your system. What you use for each component is up to you and your imagination!
You need about 5 gallons for every grown fish, and a minimum of 1 gallon per inch of fish. You can use barrels, traditional tanks, food-grade tanks, pools, or ponds. Anything that the fish can live in can be used for your tank.
This can be plastic storage containers, buckets, rain gutters or 1/2 barrels. Anything that is strong and deep enough to hold 6-12″ of medium (clay, gravel or rocks, typically).
This is what the plants grow in. Since you aren’t using soil, the purpose of the medium is to provide support for the roots and plant, and to hold some water when no water is running through the system.
The water used in your system is recycled. The water pump starts the cycling process by pumping the water from the fish tank into the plant trays. The water then flows through the plant medium and drains back into the fish tank.
The water can’t run full time. If it does, you’re roots never get oxygen from the air, and they get root-rot, effectively drowning. A timer is used to turn the water pump on and off, typically in 1/2 hour increments in a home system.
It’s important that the water gets oxygen through aeration. Fish pull oxygen from the water and so do the plants. The water stays in better balance if it is aerated. An air pump moves outside air through tubes into the fish tank.
An air stone breaks apart the air bubbles that come out of the air tubing, and more effectively aerates the water. Air stones are plugged into the end of the tubing.
Water pumped through the system runs through tubing. Black, 1/2 inch tubing is best because the black prohibits algae growth. Most pumps are set up for 1/2 inch tubing.
The air from the air pump is 1/4 inch tubing. This is your typical aquarium tubing. Black tubing, again, is best. You can also use the 1/4 inch tubing that is sold for drip irrigation systems. It’s more durable and less expensive than that sold at aquarium stores.
Managing the fish water for your tank is just like managing it for a household pet fish aquarium. When you’re starting it up, it has to cycle before it’s healthy for the fish. This means the fish have to go through a cycling process that can be life-threatening.
The cycling process requires natural bacterial to grow and consume dangerous chemicals. These bacteria grow best on porous material. Lava stone is a great medium for growing bacteria, so it’s wise to run your water through some rocks, and if you want, you can include material that filters out the sediments as well. This isn’t necessary in a pond environment, but it may be more appealing in tanks.
The biofilter medium can be as simple as gravel in the bottom of the tank, or it can be a separate system. In fact, the plant growing material may be porous enough to be used for bacteria growth, but you have to start over every time you sterilize your growing medium. Simple is good, but more prone to getting out of whack. Separate filters create more stable environments.
This is part of the fun! Our first hydroponics system is growing strawberries. You can grow any of the leafy vegetables, including broccoli, lettuce, basil, tomatoes, strawberries, etc. Avoid root crops such as carrots, turnips, radishes and potatoes. They grow best in soil environments. We know one person growing corn.
The other fun part of the process. We live in the Arizona desert, which can be hot, to say the least. We’ll be setting up a greenhouse and water cooler system to sustain our hydroponics system through the summer months. Because of our warmer climate, Nile Tilapia are perfect here. In northern, cooler areas, trout may be the fish of choice. You want to match your fish to your environment so that they grow well and stay healthy.