You use a hydroponic air pump to pump air into a hydroponic nutrient reservoir. Air stones inside your hydro tub convert the air into small bubbles. You connect these air stones to your air pump with an air-line tube. The bubbles produce oxygen inside your nutrient reservoir. The roots absorb and utilize the oxygen in the nutrient solution.
Plant root systems require water, nutrients, and oxygen. Aerating the roots improves nutrient update and water absorption increases cell growth and activity. Scientists have proven that increased oxygen to the root system can increase crop yields. Aerating the water also prevents the nutrient solution from becoming stagnant which can lead to root rot and other problems.
Hydroponic air pumps are a cheap and effective way to provide oxygen to your plants. All you need is an air pump, air stones, and an air-line to connect the air stones to the air pump.
A regular air pump designed for an aquarium is all you need for most setups. You can choose from many brands.
Some manufacturers design air pumps for hydroponics although other pumps are specifically for aquariums. However, they all do much the same thing. The pumps produce air that the air stone converts into bubbles. In turn, the bubbles oxygenate the water in an aquarium or hydroponic reservoir.
When buying a hydroponic air pump there are a number of factors to consider and specifications listed by the manufacturer. The following sections describe those considerations.
Open flow or maximum capacity is the maximum flow of air produced without any restriction on the air being drawn by the pump. Specifications typically describe the Open flow in liters or gallons per minute or hour.
The amount of air that can be pumped into a hydroponic reservoir is affected by airflow resistance or drag. You determine the airflow or drag by the length of the tubing and the depth and pressure of the solution. The greater the PSI of an air pump, the more freely the air will flow.
Air pump specifications often specify the PSI. The higher the pressure the lower the drag. A higher PSI means the air will flow more freely through the tubing into the reservoir.
Noise Level measured in Decibel (dB). Some less efficient air pumps are noisy. This can be a nuisance with indoor hydroponic growing systems. People say that air pumps produced by Secoh, a Japanese company, are almost silent in operation as well as reliable, efficient and high quality.
In most cases, we would measure maximum electrical power consumption in watts. The higher the power, the greater the airflow. While some brands and devices are more efficient than others, a general rule-of-thumb is 1 watt for every gallon of nutrient solution.
Usually measured in hours, this is the estimated time that the device will maintain the specifications given. You can improve life expectancy by replacing parts that get worn or damaged.
The number of outlets on an air pump will determine how many air stones and air-line tubings you can connect to the air pump. This is useful if you have your plants situated in a number of different buckets or barrels and need an air stone in each container. Some air pumps can have as many as 12 outlets.
Air pump tubing size is the inner diameter of the tubing. This tubing is connected to the air pump valves. The specifications usually specify either inches or centimeters.
The price of an air pump will depend on the brand, wattage, materials, and accessories that come with the air pump. You don’t have to spend much on a hydroponic air pump. You can buy a cheap air pump for around $20 – $45 that would be suitable for most indoor hydroponic systems.
Another factor to consider is whether the air pump is rainproof. If you’re intending to use the air pump outside, a rainproof enclosure will protect the air pump from rain or splashes of water.
The following air pump manufacturers produce air pumps that can be used for both aquariums or hydroponic systems: Rena, Hiblow, Secoh, Alita, Koi, Medo, EcoPlus, Hakko, General Hydroponics, and Danner.
Stones come in different shapes and sizes with the most common being golf ball or cylindrical-shaped. Air stones convert air from the hydroponic pump into a gentle flow of bubbles that rise to the surface. Oxygen is essential to plant. The nutrient solution absorbs the oxygen in these bubbles so the plant roots can use it effectively.
Micro-pore diffusers are similar but superior to air stones because they produce a larger quantity of smaller more prolific bubbles over a larger area. They tend to be more long-lasting than air stones and do not clog up so easily. Manufacturers create diffusers with kiln-fired ceramic material that does not react with nutrient solutions. You can buy single or double micro-pore diffusers.
You can connect air dividers or port manifolds to an air pump to create multiple outlets for several air stones or diffusers. This provides a much greater spread of oxygen.
Similar to air dividers or port manifolds, gardeners use airline tees for adding an additional line to an existing air-line or making two outlets from one pump outlet.
Often made of clear silicon air-line tubing fits your pump or manifold and allows air to flow through easily to the air stone or micro-pore diffuser. You should use the same length of line to each stone for equal delivery of air into the water.
Air pumps require regular maintenance every few months. This can involve replacing diaphragms and filters to keep them running. You should buy an air pump from a manufacturer that you can easily obtain spare parts from. The Tetra Whisper AP300 is one of the best hydroponic air pumps on the market and a replacement kit should only cost a few dollars and are readily available.
Make sure you have a non-return valve in the air-line to stop the water siphoning back up the air pump and destroying it. This can happen when the pump is positioned below the reservoir.
You should replace valve blocks when the pressure fails or when the pump is functioning less efficiently. These valves do wear out over time and this can result in air leads and lower efficiency. You can lengthen the life of these valves by changing your pump’s air filter monthly.
These filters are usually round and mounted to the bottom of some air pump models. They should be replaced when dirty to avoid damage to the air pump valves and to reduce the chances of the diffusers becoming clogged up.
Over time there will be a buildup of salts from your nutrients, these can clog up your air stones. However, you should be able to remove the clocked materials using a soft toothbrush.
To learn more about other aspects of hydroponic gardening, see the following sections of our guide.