Research shows that water treatment with ozone increases productivity at RAS aquaculture systems

Three reasons why ozone in aquaculture improves water quality and increase aquaculture productivity

As recirculating aquaculture systems (RAS) operate by reusing the fish tank water it is essential to control the water quality. Many studies show that treating RAS systems with ozone increases productivity as fish health and survival is increased.

At RAS the organic load tends to be high and the homogeneous fish stock leads to a high risk of infections and problems with bacteria, fungi, and viruses. Although ozone is not primarily used for disinfection at RAS the reduction of solids and DOC often creates an environment that is less favorable for bacterial growth and thus creates a reduced need for disinfection.

1. Removal of colloidal solids with ozone micro flocculation

The organic load is a constant concern for RAS systems, especially when the fish density is high and the water exchange rate low. Ozone has the ability to cause clumping or micro flocculation of fine and colloidal solids, which in turn facilitates removal by filtration and sedimentation.


Ozone changes the characteristics of the dissolved organic compounds (DOC) by oxidation and precipitation, which makes it easier to remove the COD by biofiltration.

3. Turn lethal nitrite into harmless nitrate with ozone treatment

A high organic load is a favorable environment for nitrite growth. When reducing the organic load with ozone treatment the risk of nitrite growth is also reduced. Ozone also has the ability to oxidize nitrite to nitrate.

Suffer any of the above problems with water quality at your RAS plant? Contact our Primozone Aquaculture team at

To find out more about how ozone increases productivity in RAS, please read our article published in Global Aquaculture Advocate, Aquaculture Magazine and FishFarmer Magazine.

How Primozone can help you increase productivity with ozone water treatment.

Primozone offers unique solutions for water treatment of recirculating aquaculture. We offer ozone generators and ozone water treatment systems that are specially designed for the aquaculture market. The Primozone GM-series ozone generators have several advantages that apply to aquaculture fish farming such as:

  • compact in size
  • built-in redundancy
  • easy to operate
  • low life-cycle cost
  • ozone levels automatically controlled by redox/orp values in each tank
  • ozone distribution module that can distribute ozone to several different tanks with individual ozone dosage

Main benefits

  • INCREASE - Overall plant productivity
  • FASTER GROWTH - Increase in slaughter weight
  • DISINFECTION - Reducing the risk of disease outbreaks in RAS environment

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