**Important - There are more and more "artificial-free" red food coloring dyes coming onto the market. This is great for our food consumption, but this type of dye will get through the filters and provide a false/inaccurate reading of a defective filter. We're seeing this more and more with our customers who then think their filters are defective, when in fact they are NOT.
The red food coloring MUST be artificial using reds FD&C 40 and/or 3. The test only works with this artificial red dye, and the filters are designed to remove this out. If the artificial red dye makes it through, then you have a defective filter.
The Black Berkey red food coloring test provides the opportunity to showcase the impressive purification power of the Black Berkey elements. Many water filter companies make claims to their high quality, but Berkey water filters go one step further by making their lab test results public and presenting demonstrations such as the red food coloring test. While helpful for new customers to see the Black Berkey filters in action, it is invaluable for the existing customer base since it can be used at anytime during the life of the filters to ensure they are working to design specifications.
Whether the original black berkeys have been in operation for the past 3, 7, or 10 years, one can perform this test at anytime to see if it's time for a replacement. We recommend customers place a cup underneath each filter as this will help isolate which filter is exhausted, and which is still purifying effectively.
With other water filters, the customer must assume their system is working to specifications or spend the time and money to perform water tests. This time lapse video shows how simple the red food coloring test can be done after priming your Black Berkey filters.
To perform a food coloring test, start with an empty system (upper/lower chamber), remove any PF-2 filters that may be attached, and place a glass in the lower chamber directly underneath each black berkey filter. Next, fill the upper chamber with water and add 1 teaspoon of red food coloring for every gallon of water (only red please). After 5-10 minutes, look to see if any of the water in the glasses are red or have any pinkish tinge. If one does, then that particular filter above it is defective or saturated/exhausted.