An aquaponics system needs water pumps to function properly. For your aquaponic system to continuously circulate water and deliver nutrients to the fish and plants, you must have a suitable and effective water pump. Building and maintaining your own aquaponics system could fail if your water pump is not dependable enough to complete the job of distributing the water in the system.
What Kind Of Pump Do I Need For Aquaponics?
There are two main types of aquaponics pumps: inline pumps and submersible pumps.
An inline pump is also referred to as a centrifugal pump and is generally used for larger systems. These water pumps are placed outside the tank and can move greater volumes of water. However, an inline pump is not measured by the volume of water that it moves but is instead measured in HP (horsepower).
A major benefit of using an inline pump is that the air helps counter any heat produced by the pump. These pumps are also used for aerating the water by targeting the water with high-pressure air at low volumes. The aeration facilitates the oxygen supply to the plant roots.
Benefits of an inline pump:
- Helps with the aeration of the plant roots
- Air can reduce the impact of the heat produced by the pump
- Greater power compared to submersible pumps
- Higher durability
Drawbacks of an inline pump:
- More expensive than submersible pumps
- Noisier than submersible pumps
The second type of pump is a submersible pump and is placed inside the fish tank. The water is transferred through a hose located at the crown of the pump. Submersible water pumps are measured through GPH (Gallons per Hour) and can only pump a limited amount of water. Submersible pumps are almost always used in smaller aquaponics systems where the water demand is less than 1,200 GPH. Since a submersible pump can operate while submerged in the water (hence the name), it can stay cool.
Benefits of a submersible pump:
- Costs less than an inline pump
- Easier installation
- Easier usage
- Produces less noise compared to an inline pump
- Desirable for smaller aquaponics systems
Drawbacks of a submersible pump:
- If damaged can be hard to repair
- Not suitable for larger aquaponics systems
- The seals can corrode over time
What Size Pump Do I Need For My Aquaponics System?
There are three steps involved in determining the pump size for your aquaponics system:
- Measuring the head height
- Measuring the GPH (Gallons per Hour)
- Combining the head height and GPH
Step 1 –Measuring The Head Height:
The distance between the required water level for the growing bed and the water level of the tank, is referred to as the head height. Hence, measuring the head height simply involves calculating this distance using a measuring tape or ruler.
The greater the head height is, the stronger the pump will need to be to get the water to the desired water level. In order to maximize the efficiency of the system, make sure to keep the heat down to as low as possible. In certain aquaponics systems, the grow bed and fish tank are at the same level – for such systems, the head height is zero.
Step 2 – Measuring The GPH (Gallons per Hour)
Next, you need to determine the GPH for your water pump. In general, pumps will mention their GPH, which will indicate the number of gallons of water that the pump can supply in one hour. In regions that use the metric system, this measurement might be provided in LPH (Litres per Hour).
Normally, you should choose a system that can circulate the full volume of water in your tank, at least every couple of hours. In other words, your pump should be able to cover half of your tank’s water requirement every hour. For instance, if your system has 150 gallons of water, you need a pump that has a GPH of at least 75 (150 divided by 2).
Step 3 –Combining the Head Height and GPH:
Once you have both the head height and GPH, the final step is to combine the two measurements. Most water pumps have a chart that combines the head height and GPH. This chart or curve is present in the pump’s data sheet or user manual.
To correctly read the chart, start by looking at the head height (usually located on the Y (horizontal) axis) and locate the head height that you calculated for your aquaponic system. Next, turn to the X (vertical) axis denoting the GPH, and locate the desired flow rate for your system.
The point at which these two numbers intersect is the minimum ‘working point’ for your pump.
Choosing an Aquaponics Fish Tank:
To pick the ideal fish tank for your aquaponics system, you cannot ignore the grow-bed size. Grow beds and fish tanks go together, which means that the size of one influences the size of the other. The volume of water in the system will be affected by the capacities of your grow bed and fish tank.
Grow Bed to Fish Tank Ratio:
The grow bed to fish tank ratio should generally be 1:1. In other words, there should be an equal amount of space between your grow bed and fish tank (22 litres, or 6 gallons, of fish tank space for each cubic foot of grow bed space). This ratio can increase to 1:2, but in that case you’ll need to reduce the number of fish in the tank per square inch. This is due to the fact that a 1:2 ratio may prevent your grow-bed plants from effectively filtering your tank water.
You must remember that the 1:1 ratio is only a recommendation. In reality, the ratio can be determined by a number of factors, including the system, the kind of fish that you house, and your geographic location.
Factors to Consider when Choosing an Aquaponics Fish Tank:
- Tank Shape:
Aquaponics tanks typically come in two different shapes: rectangular/square and oval/round. For the following reasons, an oval or round tank is preferable:
- It allows evener water circulation
- Uses centripetal force to transport any solid wastes towards the center of the tank
- Provides a good water flow and enables the fishes to swim against the current, thereby improving their health
- Strong water movement increases the tank’s surface area. The surface water changes also improve the oxygen exchange
- Round tanks enhance the fish’s oxygen benefits, while also nitrifying bacteria present in the system. As a result, such a tank can restrict the growth of harmful bacteria
- A round tank makes it easy for the fish to circulate
- Solid wastes will not adhere to the tank’s corners, and will instead suspend in the water
You can also go for a square-shaped tank, but you will have to regularly get rid of any solid waste materials. A square tank works best for restricted spaces.
Water tanks having non-geometric shapes or irregular bends and curves can produce dead spots within the water that completely restrict circulation. These dead areas can accumulate waste, leading to threatening conditions for the fish. If you are using an irregular tank, you must supplement it with a water tank to ensure adequate circulation, and also regularly remove any solid waste materials.
Fiberglass or inert plastic should be used for a fish tank, due to its longevity and durability. Other than that, these materials are easier for plumbing purposes, light, inexpensive, and easily movable. Avoid using a metal, since metal is prone to rust.
The tank needs to be fully waterproof. If you plan on buying a second-hand tank, make sure to first fill it with water to identify any leaks. If you do find leaks, seal them using marine-grade rubber or silicone.
The tank should be capable of withstanding the weight of the water, the water stress when it expands and contracts, and the weight and movement of the fish.
- Free of Toxins:
The tank should not contain any materials that could prove harmful for the plants or fishes. Make sure that only food-grade items were used in the manufacturing of the tank.
Do You Need Aquaponics Pumps?
Yes, a pump is an essential part of any aquaponics system. It ensures effective circulation of the water, thereby enhancing the efficiency of the entire system. This circulation makes sure that your fishes and plants receive all the required nutrients.
Other than that, a water pump brings the water up to the desired height for your grow bed. This is especially crucial in vertical aquaponics systems where you need to lift the water from the tank all the way up to the grow bed.
The water is the lifeblood of an aquaponics system, responsible for supplying nutrients to all living beings involved. Hence, you can think of a water pump as the heart of this system. If the heart is pumping too fast, too slow, or shuts down completely, it will have an immediate and severe effect on all the organs dependent upon the nutrients.
With a reliable pump, you will even be able to leave the system unattended.
Where Do Aquaponics Pumps Go?
When using a submersible water pump, the pump is submerged inside the water. Meanwhile, the larger, inline pumps are mounted outside the fish tank. Therefore, the type of pump you select will determine where the aquaponics pump is installed.
Final Thoughts on Aquaponics Pumps
To sum up, this guide attempted to answer the most essential questions that someone looking to buy aquaponic water pumps might have. To learn more about aquaponics pumps and farming, please feel free to check out some of the other blogs on our website.