HOW DOES A COLDSTREAM FILTER WORK?

This is a common question but a very important one too. As a consumer, you want to know that the water filter you are purchasing comes from a reliable company, works efficiently and effectively. Here at KLT Filtration Ltd, our Coldstream range of filters and purifiers have been expertly manufactured and rigorously tested to a higher standard than industry requirements. 

In this particular piece, we are going to explain the three main principles of how the ceramic material, used in Coldstream Sentry and CTO Plus water filters and the Coldstream Max purifiers, works and keeps your water safe. The three principles are entrapment, biocide and adsorption.

The outer ceramic used on Coldstream water filters and purifiers works using a combination of entrapment and biocide. It is made using a highly controlled process unique to Coldstream that creates a very high quality ceramic. The ceramic is made from a range of naturally occurring materials, mostly diatomaceous earth. These are fossilised microorganisms which are formed from calcium carbonate or limestone. Their structure has a high surface area and when built into a ceramic, it creates a complex porous structure.

This structure entraps particles, bacteria and other microorganisms that are in the water. The ceramic also contains biocides. In the Coldstream Sentry and CTO Plus filters, this material is toxic to bacteria and in the Coldstream Max purifier, it is toxic to both bacteria and viruses. All the biocides used in Coldstream products are harmless to humans. 

Once the water has passed through the ceramic and the particles and microorganisms have been removed, the water enters the carbon layer. The carbon removes chemical contaminants in the water through a process of adsorption. Adsorption is the adhesion of atoms, ions, or molecules from a gas, liquid or dissolved solid to a surface. Coldstream water filters and purifiers are tested for removal performance for some 70+ contaminants simultaneously. This testing represents a worst-case scenario and it is unlikely that any specific water supply will contain all of these contaminants. 

For more information and to purchase a Coldstream filter or purifier, go to the REPLACEMENT FILTERS page. 


  • Max purifier process
  • CTO Plus Filter process
  • Sentry Filter process