It is important to test Black Berkey Filters to make sure everything is installed correctly and that the filters are working properly. Red dye is most commonly used because it is a highly visible contaminant. It is a substance that can be easily seen, making the test easy to confirm. It also has a molecular structure that is blocked by the purification process of the filters.
The red dye makes the test easy to do at home because it is so visible and makes a clear distinction if the test fails or passes. If the water is clear--all's well. If the water is pink or red-tinted--the test failed, and your system is not set up properly, or one of the filters is not working as it should.
If that happens, it's important to first double-check the correct placing of all the pieces, specifically the washers and wingnuts. The washer should be in the upper chamber, and the wingnut should be in the lower chamber. Be sure not to over-tighten the wingnut causing the stem threads to be stripped, which would allow unfiltered water to pass through.
It is red because the ingredients in the red dye are completely artificial and can mimic that of contaminants commonly found in water. It needs to be diluted as it is extremely concentrated, and if put right on the filters--it can overwhelm them as it would be more concentrated than anything found in water.
Other colors of dye do not work for this test because they usually contain minerals. One of the great benefits of Berkey is that it does not remove minerals because they are beneficial for human body functioning. Therefore the dye would pass through.
Reminder: Always remove fluoride filters before performing the Red Dye Test.
Why would the test fail after confirming proper installation? It may be defective filters. The filters can occasionally fail due to damage in shipping or other reasons. However, Berkey Filters has accounted for that and has an excellent replacement warranty policy. Visit our Help Center to proceed with getting failed filters replaced. The warranty is time sensitive, so it is very important to test filters when you first receive your Berkey.