Red Mc Cormick® dye

McCormick® dye, imported from the USA, is the recommended dye by Berkey® manufacturers for testing your system.
It is preferred due to its red, artificial colour and its composition, which excludes glucose, E330, thickeners, and other colorings like E110 (a yellow derivative) that could affect test results.

When to test your system?
THe purpose of this test is to ensure your system is correctly installed and free from internal leaks. We recommend conducting this test after initially assembling your system, after removing or replacing Black Berkey® elements, or after first use following extended drying and storage of the elements.

At the end of life of your Black Berkey® filters: As your filters near their estimated lifespan (see the calculation method in our FAQ), perform the test to determine if they need replacement.
Ensure proper sealing of your system: if the test fails, it indicates insufficient sealing around the blocking plugs (for models with 4 holes and more) poor wing nut tightening, or a faulty wing nut. Follow the checks detailed in the instructions available here if necessary.
Filtration of water other than tap water: If you filter water from sources such as wells, water collectors, boreholes, or other non-tap sources, ensure correct assembly and propoer filter function. Refer to manufacturer's recommendations for these scenario (available in our FAQ).

Capacity: 10 ml for 8 tests, as per instructions
Composition: Water, Propylene Glycol, FD&C Reds 40 & 3 and Propylparaben
Instructions for use available in the FAQ