Most aquaponics systems fall into three basic categories.
They are media filled beds, nutrient film technique and the deep water culture system. Within each category there are endless variations in the design and construction of individual systems. The important thing is that the plants and fish co-exist in their separate environments.
Specific local high and low temperatures are examples of factors that cause variety in different setups. Local conditions such as wind intensity and the local weather quirks will cause some concerns, as well as the position of the sun and orientation of the grow beds.
A major determinant in the final design will be the budget and scope of the project. Small system built for residential use will share little resemblance to a large commercial system. However, most aquaponics systems are derived from these basic systems.
1. Media Filled Beds are containers filled with a growing media which is usually commercially manufactured. Water infused with fish waste is flooded into the media to nourish the plants. The media should be pH neutral to avoid affects the plant’s absorption of minerals. The media should also be shaped to provide good surface area and air voids. This type of system has been used successfully by countless farmers and it relatively low cost and easy to get started.
2. Nutrient Film Technique: Enclosed gutters are circulated with the water from the fish tank and the plants are grown in plastic containers where the plants root feed off the nutrients. The flow is only a thin film. This method works well for lettuce and other leafy green vegetables, but is not well suited for larger plants or plants with large root systems. This method of farming is also very commonly used in hydroponic systems. The gutters are slanted to allow the water to gravity drain to the next level in the system. You will need solids removal and a bio filter built into the system as well.
3. Deep Water Culture: Plants are floated on the surface of a pond or channel and the roots hang down into the water. The plants live on a floating raft that is either directly on top of the fish or else in channels where water is circulated from the fish tank. Because the size of the water reservoir is typically larger in these systems, the temperature and pH is fairly stable and easier to control. It is important to maintain good aeration and a moderate circulation rate.
Flood and drain media filled beds are simplest and most reliable systems for beginners. It can be done in a variety of different containers and you can use recycled materials. The flood and drain system also doesn’t require extensive maintenance.
Deep water culture is at the opposite end of the spectrum with large scale and big production as the calling cards of this method. Expansion potential and flexible production make this another great choice for commercial growers.