Our fish and plants need oxygen to survive. The traditional method of supplying air into the water is to use an airstone with an air-pump.

Here are a few drawbacks of air stones:

• It needs constant power
• Need to purchase air pump, airstones, and tubing
• Need to clean stones often

A venturi deals with the drawbacks of traditional aeration in aquaponics systems.

What is a Venturi Aerator?

A venturi aerator is a device that increases the dissolved oxygen (O2) of the water.

The sole purpose of a venturi is to increase the dissolved oxygen in the water without the need of an air pump.

How Does a Venturi Work?

The following image is a cross-section of a venturi. I will briefly describe how it works.

The fluid get’s pumped into the venturi from the left side (1). It then gets pushed through the narrow passway (2) where the pressure is lower according to the bernoulli principle.

The narrow passway increases the velocity of the water. The water expands after it has passed through the narrow passway. The expansion also creates suction. If an air tube is put at this stage, the air will get sucked in and mixed with the water.

How do you make a venturi?

Although there are commercial venturi’s available, you can make one on your own.

This how you make one:

You need to put the venturi right after the pump before it enters the system.

Use a 1-inch pipe which reduces to 3/4 inch. Drill a hole on top of the 3/4 inch elbow and insert a flexible PVC tube which is cut at a 45-degree angle. Using this size will be capable of delivering 900 gallons per hour.

If you are not keen on making one yourself, you can always order one from Amazon.com for a reasonable price.

Click here to see which venturi I recommend getting.

Check this video out by Rob on how to make a DIY venturi: