How to Choose the Right Air Pump for Aquaponics

One factor that contributes to the health of an aquaponics system is the dissolved oxygen (DO), which is required by:

• Fish for respiration.
• Plants for nutrient uptake, root strength, perspiration, and health.
• Bacteria for converting fish waste into nutrients for the plants.

When the dissolved oxygen is low, fish, plants, bacteria, and other aquatic organisms will not survive, which will result in a failure of the aquaponics system. 

Traditionally, oxygen dissolution is done through aeration, introducing fine air bubbles in the water via air pumps. This article will share what you should know about air pump aquaponics, why it is essential, and learn more about the factors you need to consider in choosing the right air pump. 

 

What is Aeration in Aquaponics?

Aeration is the process of creating water movement in order to promote a high dissolved oxygen level to supplement the oxygen requirements of an aquaponics system. This is done by moving water flow or by using air stones. A high oxygen level is needed in aquaponics water to offset the lack of oxygen created by the breakdown of waste, fish consumption, and algae need. The aeration in an aquaponics system can be implemented in two ways:

1. By using water flow to disturb the water surface.
2. Using aerators to disrupt the water surface. 

There are several ways of promoting high dissolved oxygen levels in aquaponics. However, using an air pump is one of the best ways to promote high oxygen levels because of its portability and efficiency. It is also ideal for backyard aquaponics home growers because it suits well into small systems. Spray pumps are cheaper, but it is less efficient, and the paddle-wheel is more suitable for larger ponds or systems. So in this article, we will focus on the use of air pumps. 

 

What is an Aquaponics Air Pump?

Air pumps force oxygen into your fish tank and grow beds so that the plants and fish will have an enough supply of oxygen. Fish and plants are prone to stress whenever changes in an aquaponics system's temperature and oxygen level. So an aquaponics grower must ensure the ecosystem of his aquaponics system is consistent. 

If your system does not have enough oxygen supply, the roots of your plants will rot, and the fish and bacteria might die. So an air pump combined with air stones serves as an emergency aeration if your water pump fails. 

• Oxygen requirements for fish: Fish can survive within a dissolved oxygen range of 5-12 mg/L.
• Oxygen requirements for plants: Plants require a dissolved oxygen range of 4-12 for respiration. 

Factors to Consider in Choosing Aquaponics Air Pump 

These are some things you need to consider in choosing an air pump for your aquaponics system.

Air Pump Size

Air pumps vary, and the size and type of air pump you need will depend on the quantity and size of fish per volume. Here are some key questions you need to ask yourself when sizing the air pump for your system.

1. What is the size of your fish tank, and how much water do you have?: The volume of water directly affects the amount of oxygen that will be required in the system. 
2. How many and what kind of fish do you have or plan to have in your system?: The number of fish is the most important component that dictates the amount of oxygen required to keep the whole system healthy. The more fish you have, the more oxygen is needed for the system. 
3. What will be the flow rate and the pump size needed to circulate the water?: The flow rate will determine how fast the water will move through the system, affecting how much oxygen can be absorbed in the water. A fast-moving water will absorb more oxygen because of its higher turbulence.
4. How big the air pump will be, and how many air stones are needed to maintain a safe oxygen level?:Generally, the safe level of oxygen in aquaponics is6.0 mg/L or above. A well-designed aeration system can positively affect the health of your aquaponics system. So carefully size your system and the air pump you're planning to used to ensure they are the right size.

You can use the guide below to choose what size of the air pump is right for your aquaponics system.

Water Volume (Liters)

(You need to calculate the total volume of your fish tank, grow bed and sump tank.)

Air Pump’s Output(Liters per Hour)

<100

150

100-200

510

350-700

1900

1000

2100

 

Noise

Pumps are usually noisy, but some models have bearable sounds. You will be using the air pumps a24/7, so it is ideal to choose one where the sound is tolerable. 

Quality

Before purchasing an air pump, always check the quality and compare the features with your system's requirements to see if it is suitable for your system. 

Materials Needed in Setting up an Aquaponics Air Pump

1. Airline Tubing

The airline tubing is attached to the nozzle of the air pump. It transfers compressed air to the fish tanks and grow beds. The tubing is made of flexible plastic, making it easier to adjust depending on the system's configuration.

2. Air Stones

The air stones are porous stones that are attached to one end of the airline tubing. Air stones help in diffusing air into the fish tank.

3. Selecting Air Stones for the Pump

Knowing from your chosen pump, you will have a flow rating of liters per hour. For example, it's a 60 liter per minute pump; you can have 5 air stones which will have a flow of 12 liters per minute each. You need to choose an air stone designed for the flow of 10 liters per minute to achieve maximum results.

 

Where to Place the Air Stones in Your System? 

• In a media bed system: Place them in the fish tank because fish need dissolved oxygen.  
• In a raft system or DWC: A raft system needs more oxygen than the media-based system because the roots are permanently submerged in the water. You can also install your air stones in the fish tanks or biofilter. 
• In a Nutrient Film Technique (NFT): Install the air stones in the fish tank or biofilter because a nft system does not need as much air input as the media-based system. 

4. Check Valves

Check valves to ensure the water is not siphoned back to the air pump. You can add check valves to the air pump when placed below the tank and tubing level.

Conclusion

Air pumps are a necessary component of an aquaponics system. Because it helps promote healthier crops and ensures a safe environment for fish, plants, and bacteria. Having an aquaponics air pump will assure you that your system is in optimal conditions. Thank you for reading our article. Check our ultimate aquaponics beginner's guide for an in-depth guide in building your own system.