Water pumps are an important part of an aquaponics system. Having the right and efficient water pump will ensure that the water is continuously pushed throughout your aquaponics system to provide the nutrients to the fish and the plants. If your water pump is not reliable to do the job of distributing the water in the system, the consequences could be a failure in building and maintaining your own aquaponics system. That is why we made this article to help you choose the right water pump for your aquaponics system.
Why Do You Need a Water Pump for Aquaponics?
A water pump plays important functions in an aquaponics system, and here are some of them:
- Water pump helps in the efficient transportation of the water from the fish tank to the grow bed and then back to the fish tank again.
- Water pumps provide oxygenation on the water, ensuring that fish have plenty of oxygen in the fish tank.
- A water pump ensures that both fish and plants in the system receive the nutrients required for their optimum growth.
Things to Consider in Choosing the Right Water Pump
You need to consider two essential things in choosing the right water pump for your aquaponics system. These are:
You must know the electrical usage of the pump you are planning to purchase. This means knowing the number of watts the pump uses so that you can calculate the possible additional cost to your electricity. A lower watts used means less consumption of electricity.
2. Flow Rate
Another thing you need to consider is the amount of water that has to be pumped through the system. The water pump should be able to circulate the entire system within two hours. So if your system uses a 200-gallon of water, it should be able to pump 200 gallons of water within two hours (100 gallons within 1 hour), so you will need a pump with at least 100 GPH.
It is important to select a water pump with a larger GPH than the required amount. This will ensure that the fish in the system are supplied with clean, nutrient-rich, and oxygenated water for at least two hours. To have an effective system, it is important to purchase a water pump that can produce your system's required flow.
How to Determine the Correct Water Pump Size for Your System
In determining the correct water pump size, you need to determine the GPH (Gallons Per Hour), measure the head height, and then combine the GPH and head height.
Determining GPH (Gallons Per Hour)
The first thing you need to do in sizing the water for your system is to determine the GPH or Gallons Per Hour. Most water pumps have a Gallons Per Hour (GPH) rating that lets you know the number of gallons of water that they can pump every hour. In some areas that use the metric system, the ratings are Liters Per hour.
The rule of thumb is that your water pump should circulate the entire water volume in your system at least every two hours. So choose a water pump that can meet this minimum requirement of cycling the half of your entire system's volume of water every hour. Let's say if you have 100 gallons of water in your entire system. You will need a water pump that can circulate at least 50 gallons of water per hour. So you will need a water pump that has at least 50 GPH.
Measuring the Head Height
The head height is the distance between the fish tank's water level and the desired water level of the grow bed. In measuring your aquaponics system's head height, simply measure the distance between the two water levels with a ruler or tape measure.
Take note that the larger the head height, the more energy it requires pumping the water. Keeping the heat at a minimum level will keep the entire system efficient. But for some aquaponics systems where the fish tank and the grow bed are at the same level, there is no head height.
Combining GPH and Head Height
Once you have determined your GPH and measured your head height, the next step is combining the two variables to determine the right water pump size for your aquaponics system. In general, most water pumps come with a chart that combines GPH and head height.
This is a sample chart for the Active Aqua Submersible Pump and should only be used if you're using an Active Aqua Pump. Each manufacturer has its own specific chart that comes with the product.
Reading the Pump Curve
Every water pump has a pump curve in its user manual or datasheet. In looking at your water pump's pump curve, look at the left axis first and find the head height you calculated for your system. Draw a line to the right and look for your required minimum flow rate and draw a vertical line. The point where the lines cross is your pump's "working point."
Types of Water Pump
1. Submersible Pump
A submersible pump sits directly in the tank and pumps water through a hose attached to a fitting at the top of the pump. They are sized in GPH (Gallons Per Hour) and are limited in the number of gallons of water that can be circulated. Submersible pumps are common water pumps used in small aquaponics systems that do not exceed 1,200 GPH. The submersible pump's ability to work while being submerged in the water also helps in cooling them off.
Advantages of Using Submersible Pump in Aquaponics:
- Submersible pumps are cheaper.
- Easier to use.
- Faster to set up
- Less noisy compared to inline pumps.
- Very efficient for small aquaponics systems.
Dis-advantages of Using Submersible Pump in Aquaponics:
- Submersible pumps can be difficult to repair.
- Great only for small aquaponics systems.
- The seals can be corroded over time.
2. Inline Pumps
Also called centrifugal pumps, the inline pumps are placed out of the fish tank and are mostly used in larger aquaponics systems. These higher-powered motors are capable of moving larger volumes of water. Inline pumps are measured in horsepower (HP), not by the volume of water that they can move.
One major advantage of inline pumps is that the air cools the heat generated by the pump. Inline pumps can also be used to aerate the water by pumping low air volumes at high pressure into the water. This helps in supplying oxygen to the plant roots.
Advantages of Using Inline Pump in Aquaponics:
- It helps in aerating plant roots.
- Air cools the heat generated by the pump.
- Have more power compared to a submersible pump.
- More durable.
- More expensive than that submersible pump.
- Noisier than a submersible pump.
Running and maintaining an aquaponics system is not a hard task to do. But you need to be equipped with the right components to ensure that your investment will be a success. A reliable pump is important in every aquaponics system because it ensures that water is continuously running throughout the entire system. So you must choose and invest in the right water pump to have a successful system. Thank you for reading our article. Read our related article "How to Choose the Right Fish Tank for Aquaponics" for additional aquaponics information.