Green Life Zen

Air or liquified oxygen in an aquaponics system is frequently underrated.

In this post, I'm going to talk about my favored air pump to enhance liquified oxygen in an aquaponics system.

However first, let's find out the reason why you would really need liquified oxygen ...

Why do you really need an air pump in aquaponics?

An air pump in aquaponics is utilized to provide oxygen to your fish and plant roots. Failing in providing sufficient air for your aquaponics system will lead to the following issues:

  • Oxygen deprivation for the fish
  • Root rot in your plants
  • Dying of nitrifying germs

These are the organisms that take in oxygen in an aquaponics system:

  • Fish
  • Plants
  • Germs
  • Algae

If your pump stops working, an air pump integrated with air stones likewise serves as emergency aeration. It's a low-cost method of keeping your fish alive and offers you comfort.

Lots of pathogens grow in low air conditions. To reduce this you need to increase the liquified oxygen level of your aquaponics system.

When the temperature level of the water increases, liquified oxygen levels in water reduces. That's why the highest chance for fish deaths is in summertime.

Fish really need to extract oxygen from the water, the higher the liquified oxygen in the water, the less energy the fish really needs to extract it.

Fish like tilapia and catfish really need a minimum of 2 to 3mg/L while trout needs as much as 8mg/L. Going somewhat above these variables does no harm to the fish or your system. In fact, I urge you to have more liquified oxygen in your system.

Since they take in oxygen, you really need to reduce algae growth.

Aeration likewise supplies degassing of the harmful gasses that belong to denitrification.

How does Aeration in Aquaponics Really Works?

The aeration of an aquaponic system can be performed in two methods:

  • Utilizing water circulation to disrupt the water surface
  • Utilizing aerators to disrupt the water surface

Developing a high liquified oxygen level is done by creating motion in the water and breaking the surface tension of the aquaponics fish tank. This is done by a moving circulation of water or aeration by air stones.

Where do you put air stones?

In grow beds

In grow beds, the flood and drain cycle will provide oxygen to the roots and to the germs. There is no air supply required in the grow bed. Your fish really need liquified oxygen so it's better to put air stones in the fish tank.


A DWC system needs more oxygen than a grow bed system. This is because the roots are permanently immersed in the water. If you are utilizing a bio filter you need to set up a couple of air stones in it too. You can see that a DWC really need more air supply than a common grow bed. You likewise need to set up one or more air stones in the fish tank.


An NFT systems doesn't really need as much air input than a DWC system does. In NFT systems, the air is provided in the fish tank and biofilter.


A Deep Flow Technique system really needs extra air stones in the channels or right before the channels. Instead of a film in the gutters, DFT utilizes an inch or more of water in the channels.

Mineralization tank

If you have a mineralization tank you really need to include some air stones to them. This is to supply oxygen to the germs that break down the solids and to distribute the solids in the tank as well. I suggest setting up} a mineralization tank if you are not utilizing grow beds.

Diffusion of air in the water

Liquified oxygen is moved to the water column through diffusion. The air is diffused in the water. This is done by air stones. The smaller the air bubbles the much better. However smaller sized bubbles need more pressure from the pump. The size of the bubbles likewise depends on how large the pores are in the air stone.

The deeper you put the air stones in the water, the more difficult the air pump needs to pump since it needs to fight the pressure. So, you are thinking of putting them right under the surface? That would not be such a good idea since the diffusion of the air likewise depends upon the time it touches the water. The depth contributes in disrupting the surface. The deeper the diffuser is, the more water is moved.

Choosing an Aquaponics Air Pump

You can't oversize your air pump in aquaponics. I haven't seen any scientifically tested approach of calculating the size of an air pump in aquaponics due to the fact that there are lots of variables.

I have actually seen a formula where they determine the needed oxygen for aquaculture. The calculation can be found here.

Choosing air stones for the air pump

When you have actually chosen the air pump it's time to choose the air stones. Knowing from the pump you have selected you will have a circulation score in Liters per hour. In this example, it's a 60 liter/minute pump. It has a manifold with valves so we can manage which one we utilize. You can have 5 air stones which will have a circulation of 12 liters/min each.

We really need to select an air stone that's developed for of circulation of 10 liters per minute.

Suggested air pump setup for aquaponics

Grow bed setup-- overall installation expense = $39.
  • Hydro farm Active Aqua 6W 15L/min.
  • Paw fly air stones 2L/min.
  • 25ft air tubing.
Small DWC setup-- overall installation expense = $88.

Have your airlines the same length and your air stones at the same depth. Air takes the path of least resistance. If you want to have a similar amount of air circulation in east air stone you need to take this into account.

If you don't set up one-way valves, mount the air pump above the waterline. When the power turns off the water can come up in the tubes and end up in the water pump. That's why installing it above the water line is a great idea.

Frequently Occurring Issues

The air pump is overheating.

The overheating of an air pump mainly occurs because the pump can't eliminate all the airflow it's producing. Therefore, developing resistance in the air pump. It's much better to have another air stone connected to one of the outlets to release the pressure accumulation.

You can likewise utilize a bleed valve which 'bleeds' unused air back into the atmosphere. However that would be a waste. It's much better to include another air stone in the system.

What does it cost to run an air pump?

I'm going to calculate the expense of running the air pump I suggest.

  • The power intake is 32 Watts.
  • We run the pump 24/7.
  • Electrical power cost is $0.12/ kWh.
  • 32 watts x 24 hr = 768 Wh/day.
    • 768/1000 = 0.768 kWh/day.
    • 0.768 x $0.12 = $0.09216/ day.
    • $ 0.09216 x 365 days = $33.6/ year.

How to moisten the noise of an air pump?

The pump features rubber feet which will moisten the sound of the pump. You can likewise set up a diffuser or dampener on the inlet of the compressor.

My air stones are getting clogged up.

After a while, the air stone can end up being clogged with algae or solid waste. It's good to clean up the air stone from time to time to increase the diffusion of the bubbles. The very best of keeping an air stone tidy is to utilize a tooth brush to clean it.