Your home's water supply should ideally be clean and pure straight from the tap, but this is unfortunately not always the case. Home water filters are designed to remove dissolved minerals, microbes and bacteria, and other contaminants which may be in your water supply. However, while all types of water filters seek to fulfill the same function, each type does so in a different manner and thus has a different set of advantages and drawbacks associated with it. Understanding the differences between the most common types of water filters can help you choose the one that best fits your needs.
Activated Charcoal Filters
Sometimes also called carbon filters, activated charcoal filters work either by attaching directly the faucet, or through a pitcher filtration system that you can keep in your fridge. Activated charcoal is a material that has many extremely small holes in it, which will allow water to slowly pass through while trapping smaller particles which may be within the water, like bacteria and mineral impurities. However, activated charcoal filters can take a little while to work and will require the filter cartridge to be replaced periodically.
Ultraviolet filters are designed specifically to kill bacteria and other living organisms which may be in your water, and do so with a concentrated burst of ultraviolet radiation. They are installed under the sink or faucet that they are filtering, which means that there is no visual indication that you have a filter installed on the first place - a huge interior design plus. Additionally, since they make use of flashes of ultraviolet light to do their job, they work extremely quickly at purifying and filtering your water. However, the major downside associated with an ultraviolet filtration system is the fact that they are unable to remove dissolved minerals and other non-living contaminants - like iron, rust, or dirt - from your water supply.
Reverse Osmosis Filters
Reverse osmosis filters make use of a semi-permeable membrane, which has several microscopic holes in it, to prevent bacteria and minerals from making it out of your faucet. Like ultraviolet filters, these are installed underneath your sink, but they operate under the same principle (though are much more efficient) than activated charcoal filters. By virtue of the microscopic size of the holes in their membrane, they are able to keep out both bacteria and dissolved minerals. However, reverse osmosis filters work extremely slowly: once you've drained the tank underneath your sink of filtered water, you'll have to wait a significant period of time for it to refill (exact lengths will depend on the model). Further, reverse osmosis filters will require a fair deal of maintenance, since the filter will need to be cleaned and refreshed regularly to ensure that it stays working efficiently.
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