Understanding how the Aquaponics filter works to keep the system clean can be daunting at times, especially for beginners. Things seem to be going fine for a week or so but then you find that fish solid wastes are clogging up the system.
Solid particle waste from the fish must be dissolved. Aquaponics filters are designed to not only capture solid fish waste, but also any loose plant components and any other particles that get in the system. It can also capture uneaten fish feed including any aqua animal fish foods like shrimp, crustaceans, and others we mentioned in our Fish Food Post.
An Aquaponics Filter With Media Grow Beds
Determining the need for an Aquaponics Filter. Aquaponics systems that are built with media grow bed containers along with a nominal population of fish stock, will have sufficient enough bacteria colonization to keep the water clean. However, when the fish tank starts to get murky and show signs of sludge that isn’t getting dissolved, it’s time to consider an additional filtration device.
One scenario is when the aquaponics gardener starts adding additional containers to facilitate more plants. That means extra fish stock will be needed to keep the plants healthy. With an increased density of fish there may be be more solid waste than the grow beds bio-filters can handle. There are many filter types that can help to keep the system clean.
Aquaponics Filter Types
Aquaponics Swirl Filter
This type of Aquaponics filter requires a large barrel-shaped container with an inner cylinder basket that filters out solid waste types. It filters out the debris by slowing down the water which causes the heavier particles to descend to the bottom of the container.
The barrel needs to be cleaned out from time to time but be sure to not use soap products when cleaning. This is because the soap chemicals are harmful to the beneficial bacteria. So don’t overdo it when cleaning, you just want to remove the solid wastes so they don’t clog up the filter. The slime on the sides of the barrel contain a lot of the bacteria that will be helpful to the plants.
Swirl water filters are very popular with most grow bed types. They are available online but for the home aquaponics gardener it can be a DIY project using a barrel with 50-60 gallon capacity (give or take). Commercial systems are going to use filters that require 500 gallon capacity and more.
Raft Water Filter
Another Aquaponics filter that is efficient at screening out the bigger solids, the Raft water filter, features two chambers or filtration layers. The first chamber captures the larger solid wastes. Next the water overflows into the 2nd chamber where finer particles descend to the bottom and are left behind as the clean water is piped to the grow bed.
This type of filter is very efficient but isn’t commonly used because it can be expensive. It also can take up quite a bit of space.
Crucial to this type of filter is oxygenation of the water. This is facilitated by placing air stones ( porous stone) in the filtration device. Then there are the pumps that aerate the water by keeping the flow movement through the pipes from the fish tank into the raft chambers. Monitoring the pumps is essential because if they fail it would be catastrophic for the fish and the plants-they both need constant oxygen.
Radial Flow Filter
A radial flow Aquaponics filter is similar to the Swirl filters in that you start with a barrel of approximately 50 gallons capacity. Then a pipe is connected from the fish tank to the barrel extending inward to its middle, then angling 90 degrees upward near the top. This is where the bigger solids are filtered in a way that sends them down to the bottom of the barrel while the nutrient-rich water it piped to the grow bed.
Aquaponics Drum Filter
The drum Aquaponics filter is normally set in a box-like chamber. Inside the filter there are 2 sides, the dirty water side that is piped in from the fish tank, and a clean side that will be piped to the grow bed.
The drum itself is a barrel that rotates like a rotisory fasted to the sides of the box container. The drum is the filter as it is surrounded by a micro mesh screen. The water from the fish tank is piped into the box chamber where it is pulled through the drum via the pump.
The debris from the fish tank settles onto the mesh and as it gets more and more blocked the pump can’t pull the water through, so the water starts to drop. There is a float switch down below that will be triggered to turn on a rinse cycle that cleans the mesh. Above the drum is a pipe with nozzles that spray the mesh.
The clean water is then sent to the grow beds. This is a very efficient filter for keeping the water clean for the plants and fish.
Other DIY ways to filter your aquaponcs system are:
- Running the flow of water over gravel or porous rocks before reaching the grow beds
- Using mesh cloths at the end of the pipe that is pouring into the grow bed media.