Filter for Nitrate Removal From Aquariums and Larger Bodies of Water

Nussinovitch Amos, HUJI, Faculty of Agricultural, Food and Environmental Quality Sciences, Biochemistry, Food Science and Nutrition
Van Rijn Jaap, HUJI, Faculty of Agricultural, Food and Environmental Quality Sciences, Animal Sciences
Tal Joseph, HUJI, Faculty of Agricultural, Food and Environmental Quality Sciences



Aquarium fish are beautiful, exotic, and ornamental.  Today’s standards of aquarium maintenance stress the need for nitrate removal within the aquarium.  Nitrate is a product of nitrite oxidation during the latter stages of the nitrogen cycle and some level of it exists in all aquariums. Nitrate inhibits the ability of fish to grow, leaves them more susceptible to disease and can affect their ability to reproduce. 

Debris from decaying plant material, dirty filters, over-feeding, and overstocking the aquarium all contribute to increased levels of nitrate. Tap water frequently used to fill an aquarium also contains the chemical. Nitrate removal today is time consuming (frequent cleaning and water changes) or involves the purchase of costly filters.

Our Innovation

Our researchers have developed a technology that is superior to current nitrate removal systems. They have designed water filters with denitrifying bacteria immobilized in novel polymer carriers that effectively remove nitrate from aquarium water. The permeable polymer carriers reduce nitrate to nitrogen gas through the incorporation of a consortium of bacteria and suitable carbon source.

Key Features

  • Polymer carriers are non-polluting and contain non-pathogenic bacteria
  • The filters are effective both in freshwater and seawater aquariums
  • Denitrifying activity is sustained over a period of several months
  • The bioactive carriers can be produced in a dry form to enable a shelf life of years


  • The technology removes nitrate in both freshwater and seawater aquariums.
  • The technology reduces the need for frequent water renewal in aquariums whereby the need to replenish artificial sea salt in seawater aquariums is also reduced.  
  • Through the reduction of nitrate levels, the technology extends the life expectancy of a wide range of ornamental fish.
  • The non-pollutive carriers are able to remove nitrate over extended periods of time with little maintenance.
  • Nitrate removal from the water commences immediately upon installing the filtration unit.
  • The technology is suitable for purification of aquariums and other nitrate-contaminated bodies of water
  • The canisters containing the carriers are easy to install without the need for additional water pumps.


Contact for more information:

Ilya Pittel