The black stuff in your charcoal water filter is technically carbon. The properties of carbon allow it to remove contaminants from your water and improve both the taste and the odor. While both of these are inconveniences, they’re generally not a threat to health. While these filters are great at removing the obvious things like dirt, bad taste and foul odor, they’re also great with removing more harmful contaminants.
The most effective of this class of filter is the charcoal water filter that uses activated carbon and can even be impregnated with activated silver ions. The term “activated” is given to these filters because of an ionization process that has been performed on the material. This ionization makes the filter material more effective as it is actually able to attract contaminants from a short distance away on the microscopic level. If the material is not activated the contamination will have to come in direct contact with carbon particles for the contaminant to be removed.
This is essentially how a charcoal water filter works. It has a lot to do with mechanics. As the water flows through the filter it comes in contact with the filter media and anything floating loose in the water at a very small scale gets stuck to it. Then it stays in the media forever. That’s the reason filters need to be changed periodically. They can get filled with all the impurities that have been pulled out of the water. When this happens the carbon filter is no longer able to do its job.
Since water needs to flow over the material for contaminants to be filtered out it’s helpful for the filter material to have a large surface area. It’s the amount of surface area plus the amount of time that the water is in contact with the filter material that helps make for a more effective charcoal water filter. The most common filters use granulated carbon because they are easier to make so they can be sold for less money. But a design that gives you more surface area is called block carbon.
Activated charcoal water filters made from block carbon will give you superior water filtration properties, but this may be at the cost of slower filtration time. The block carbon is packed more tightly than granulated carbon so not only is there more surface area but there is less space for the water to get through. So even though you may have to wait a little longer you will be getting cleaner water as a result.
If your home has other problems, such as excessive iron or sediments you may need to opt for a more comprehensive solution. It’s possible to get charcoal water filters that install in the home where the main water line comes in. In the case of sediment problems you would want to install a sort of pre-filter to remove sediments before the water entered the charcoal filter media. This will help increase the life of the media, saving money in the process. Also, by putting a filter like this where water enters the home you will be able to project more than just the water at your faucet or in a pitcher. You will also be protecting the water in places like the shower and bath where there is potential to be exposed to even greater levels of contaminants.