Hydroponic Air Pump: Do You Need One


Oxygen is a primary need for plants to grow. Plant root systems generally obtain their oxygen from pockets of air between the grains of soil. In hydroponics systems, plant roots extract the oxygen they need from the air or directly from the water itself. Does this mean that you need an air pump for your hydroponics system? 

An air pump is not required for most hydroponic systems. Some deep water culture hydroponic systems require an air pump to provide enough water aeration, but this often depends on the setup and the type of plants growing in the system. Other hydroponic systems generally don’t require air pumps.

Most hydroponic system types do not require air pumps as part of their setup, but this does not mean that an air pump is not useful in any hydroponics setup. Here’s a list of our favorite hydroponic air pumps if you’re in a hurry.

Photo 127619073 / Air © Ppengcreative | Dreamstime.com

What Is The Purpose Of An Air Pump In Hydroponics?

Air pumps can play an important role in hydroponics, but it is not required for every hydroponic system. Even though all hydroponic systems don’t need an air pump, this is not to say that an air pump won’t benefit the system.

The main purpose of an air pump in a hydroponics system is to bubble air through the water to increase the amount of dissolved oxygen in the water. This ensures enough oxygen is present in the water for the plant roots to absorb since there are no air pockets available underwater.

See our article on What Is Dissolved Oxygen in Hydroponics

Air pumps can serve another purpose, which is not really meeting a need but rather an added benefit. The bubbles passing through the water create a current, keeping the water moving. This current helps to keep the nutrients dissolved in the water, especially when using power nutrients.

Inducing a current in the water can also help prevent pests such as mosquitoes from taking up residence and breeding on the surface of your nutrient water. Air pumps can also help keep the water in your hydroponics system cool if the air supply is drawn from cool air. 

You can’t over-oxygenate the water in your hydroponic system with normal aquarium-sized air pumps and cause harm to the plants. Though an air pump is not necessary for most hydroponics systems, installing one will not cause any harm but does provide other benefits.

Which Hydroponic Systems Need Air Pumps?

Hydroponic systems that do not have flowing water are the installations that benefit the most from including an air pump in their design.

The deep water culture, Kratky, and static solution culture methods are hydroponic systems where air pumps are typically utilized. These implementations of hydroponics generally have little to no movement of the nutrient solution included in their design.

Of these three methods, the Kratky method does not always require an air pump. This is because the method requires an air gap between the water’s surface and the plant’s base. The plant grows air roots in this gap of moist air, which absorb oxygen directly from the air.

Other continuous flow hydroponics systems, like nutrient film technique (NFT), ebb-and-flow systems, and hybrid implementations which combine some of these ideas, do not need air pumps. The flow of the nutrient-laden water absorbs oxygen as it moves, flows, or tumbles through the system and back into the central reservoir.

The easiest way to grow fresh, healthy and delicious produce and herbs at home is using the Tower Garden vertical aeroponic system. The Ready-To-Grow system takes all the guess work out of home growing and produces bigger yields in less time using less water. See What is a Tower Garden for more details.

Tower Garden Aeroponics System

What Size Hydroponic Air Pump Do I Need?

Unless you are building a commercial-size hydroponic system, your air pump specification does not need to be particularly impressive. Most aquarium pumps are well within the minimum range and will suit the needs of most home hydroponic systems.

For most small installations, typical aquarium air pumps will be sufficient. The minimum requirement would be a 500cc to 600cc per minute air pump for a small system. The capacity of the air pump should be sized according to the volume of nutrient water in your reservoir.

The basic guideline is 500cc to 1000cc per minute for each gallon of water in your reservoir. Remember that you are not filling your reservoir all the way to the top, so a 5-gallon bucket will typically have between 3 to 4-gallons of water. So, for a bucket with 4-gallons of nutrient water, you would need an air pump with a capacity of 2000cc per minute to 4000cc per minute. 

What Is An Air Stone And Do I Need One For Hydroponics?

An air stone is a porous rock that spreads the air delivered by the air pump over a wider water area. The air stone also reduces the bubble size from large bubbles to many tiny bubbles. This increases the surface area of water that comes into contact with the bubbles, increasing the amount of oxygen the water absorbs.

Some air pumps come with multiple outlets, which gives you the option of connecting multiple air stones to the pump and distributing them in different reservoir areas.

This configuration also gives you the option of aerating more than one reservoir from a single air pump. Air stones are not required for hydroponics, but they can be useful for distributing the airflow in the reservoir.

Why Is My Hydroponics Air Pump So Loud?

Air pumps sit outside of the nutrient reservoir, where the motor noise is easily heard. Hydroponic water pumps typically reside in the water in the reservoir, which significantly reduces any noise produced by the water pump.

Air pumps generally have the noise level of the pump indicated on the packaging of the pump in Decibels, or Db. Some pumps have a lower noise factor than others but expect to pay more for a higher quality pump that produces less noise.

The ideal noise factor you should be looking for is an air pump that produces less than 45-Db. At less than this level, the noise produced will fade into the background rather than being a source of annoyance.

Parts Of The Hydroponic Air Pump System

In most cases, the air pump is sold by itself, and any additional components are extra. For a complete air pump setup for your hydroponics, you will need an air pump, some piping, and an air stone.

While an air stone is not a requirement, it helps distribute the air through the water more effectively. The piping can be any form of airline tubing, preferably a dark color rather than clear.

Clear tubing will promote algae growth in the tube due to moisture drawn in by the air intake. Dark-colored tubing will prevent light penetration, limiting algae growth.

Conclusion

An air pump is not necessary for most hydroponic systems unless you are using one of the static water systems, such as a deep water culture hydroponics system. The other hydroponic systems have sufficient aeration of the water due to the movement of the water through the system.

However, an air pump in the nutrient reservoir of any hydroponic system can provide beneficial water movement and temperature control.

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