For millions of people across the country in areas with substandard municipal water provision, a single water filter, an installed water filter, or a whole-house water filtration system is one of the things people most commonly turn to. It is either that or investment in bottled water or special water products such as purified, filtered or hydrogen water, which is known to offer health benefits over and above what has come to be expected from even the best municipal water. 

Synergy Science, a water products company specializing in alternatives to tap water, report that a water filtration system will never be able to provide a steady and unlimited supply of any water products that have beneficial additions. They can provide excellent filtered water to the home, with many of the contaminants which effect taste – and which even harm health in the long run – successfully removed. This is the way of water filtration, at any rate. Before purchasing a water filtration system or an alternative water product though, most people are just as interested in the ‘how’ of water filtration.  

The General Principle

How water filters work depends very much on the type of filter, or how the filtered water you have purchased has been filtered. There is quite a big different, for example, between purified, distilled, and filtered water, and just as much of difference between the different home water filtration systems. 

Nevertheless, there is a general principle behind all of them, and that is to remove contaminants. The principle of all filtration is to create a barrier that only lets particles below a certain size through. The good stuff in water – including the H2O molecule which is water itself – is all on the smaller end of the scale. Contaminants are generally larger and filtered out as a result. Contaminants can, however, be dissolved in water too. In such cases, filtration works thanks to chemical reactions with the filter substrate, allowing only certain compounds and molecules to pass through. 

This is the difference between physical size filtration, which removes suspended particles, and chemical filtration, which removes dissolved substances. 

Different Types of Water Filtration

There are several kinds of filters, each of which function quite differently to each other. The following two are the most common:

Carbon Filtration 

Also known as granular carbon filtration, this system works by trapping contaminants with a mass of porous carbon packed into the substrate. You can think of this carbon as having many tiny holes, increasing the surface area which contaminants can bond to. These systems often include a physical filtration system, such as sheet of fabric, in order to remove larger suspended particles. 

Reverse Osmosis Filters 

Reverse osmosis filters work according to quite a different principle. They are also less common and will always require installation. They work with semi-porous membranes (several of them, with differently sized openings) to filter the water several times before it leaves the system. Such filters can effectively remove more contaminants than carbon filters. However, bear in mind that at this level of filtration, some of the “contaminants” removed can actually be beneficial for health. Nevertheless, this is the best way to get as close to purified water as possible.


This then is how filters work and what they can do for you. It must be noted that they all only remove substances from the water and do not offer additional substances that can be beneficial. For that, the alternatives are, clearly, purchased water products with a formula optimized for health. 

Nonetheless, anywhere there is sub-standard, or even dangerous, municipal water, water filtration systems will always have their place.