Mold is never a good thing to find, especially in your Berkey® System. The good news is, mold can be easily removed and prevented. Mold growth is in the upper chamber of the Berkey® System, where the unpurified water enters the system, though in some cases it can pop up in the lower chamber as well
Remove the Black Berkey ® Purification elements and scrub them with an abrasive pad or toothbrush. Reprime the elements to flush out any old water. The Black® Purification elements are self-sterilizing, which prevents any bacterial growth inside the filter.
To clean the stainless steel housing, wash both the upper and lower chambers with warm water and a few drops of plain bleach that doesn't contain any artificial scents or additives. The bleach will effectively remove the mold and kill off any bacteria in the chambers. After these steps are completed, you can reassemble the system and begin purifying your water again.
There are two common causes of mold growth. The first is that water has been allowed to sit in the system for too long. We recommend changing the water in the system at least every three days. If you plan to leave town for an extended period of time, empty the system and follow the proper storage procedures for the filters.
The second cause of mold is heat. We recommend that you avoid placing the system in direct sunlight, as this can cause the system to heat up, creating the warm and damp situation that encourages mold. This is especially important for systems like the Berkey Light®, which can also cause algae growth when placed in direct sunlight .