Have no fear--that's normal and a-ok. That's the visible proof that the water you're drinking doesn't have THAT in it.
Over time, as contaminants bond to the carbon, they can clog the pores and make it harder for the water to pass through the filters. Cleaning your filters with a 3M non-scratch Scotch Brite Pad will strip away the outer layer of the carbon where the pores are clogged. This will expose a fresh layer of carbon and allow the filters to work at a faster pace.
You will want to clean the filters anytime the flow rate slows down or have any visible scum on their exterior. Always prime the filters after cleaning them to rid of any air pockets within the filters. They are manufactured to sustain up to 100 cleanings in their lifespan. Proper cleaning is the key to the longevity of the filter’s lifespan.
What are the Floaters in My Berkey Water?
Floaters sometimes occur with hard (heavily mineralized) water. When the pH level of the filtered water is raised, the acidity of the water goes down, and the water is no longer able to hold as many minerals in the solution. Because of this, the minerals begin to build up over time. Depending on the mineral composition, they will either sink to the bottom or float to the top. This process is known as flocculation, and the precipitated minerals are usually referred to as "white floaters."
Rest assured, this is not to raise concern, and the floaters are not harmful. They are minerals already in your water, and now they are visible, whereas they were previously invisible due to their suspension in an ionic form.