Superficially looking at it, boiling water cannot be the same as filtering water. Of course, both are water purification methods. But the chemical and physical processes involved differ considerably. Brace yourself now for a detailed analysis. Let’s kick off with boiled tap water.
How boiling water works
The practice of boiling water has been there for thousands of years. Some people choose to first mechanically sieve the water in case it is cloudy. This gets rid of most of the suspended solids. The next step is to pour the water in a pot or pan and bring it to boil.
When the temperature of water is raised to boiling point, the harmful bacteria in the water succumb to the high heat. Note that the boiling point of water is 100 degrees celsius, and many pathogens cannot survive in water once the 70 degrees celsius mark is surpassed. Boiling also removes chlorine through evaporation.
However, the dissolved minerals present in water aren’t affected. Boiled water retains most of the minerals present in tap water, which benefits your health. But this fact has a downside to it, given that toxic contaminants such as lead remain untouched. Furthermore, boiling tap water that has lead content makes the lead even more concentrated per litre of water.
This can be partially solved by boiling the water for about 15 minutes so that some of the dissolved minerals precipitate and attach to the surface of the pot. You must have seen the whitish deposits in hot water kettles and boiling pots. Overboiling, however, removes vitamins and other essential micronutrients present in water.
How filtering water works
When it comes to filtering, you can choose from a number of filters, including but not limited to;
- Reverse Osmosis water filters
- Activated carbon water filters
- Ultraviolet water filters
- Sediment water filters
The level of filtering achieved depends on the type of filter you choose. Some are good in filtering out chlorine, others good in killing pathogens, others specialized in getting rid of suspended solids, while others like RO water filters effective in getting rid of nearly every contaminant in water.
Whatever type of filter you choose, the idea is to pass the water through a chamber with a gauze-like material that traps the contaminants. In other filter types (such as in activated charcoal water filters) the chemical process referred to as adsorption is used to stick the contaminants onto the surface of the filtering media. For UV water filters, UV light is used to disinfect the water, making it free of disease-causing bacteria and viruses.
Differences between boiling and filtering tap water
- Initial cost – Boiling is generally cheaper than filtering water. For boiling, you only need a pot and source of heat, whereas for filtering you have to purchase a water filter and have it installed. Water filter prices range widely, anywhere between 20 and 500 bucks, depending on the brand and filtering technology you choose from.
- Running costs – In the long run, boiling water ends up to be more costly than filtering water. Water filters consume very little energy compared to hot water kettles.
- Carbon footprint – Taking into account fuel consumption, boiling water has a higher carbon footprint than filtering water
- Time requirements – Boiling water consumes more time than filtering water, and this is amplified when you need the boiled tap water to cool before drinking. With filtering, a mere touch of the button does it all.
- Mineral retention – Boiled water is more or less similar to tap water in terms of mineral content. Note, however, that overboiling can kill some vitamins and micronutrients. Filtering may or may not remove essential water minerals – depending on the type of filter you use.
- Taste – As boiling water removes chlorine, the bleach taste disappears. But remember that the water may acquire other queer tastes as the dissolved solids get more concentrated. Activated carbon water filters are the best in enhancing the taste of water and ridding it of pungent smells. RO filters are likewise good. Other filters may not significantly improve the taste of water
- Disease safety – Boiling effectively kills most microorganisms. Some types of water filters such as sedimentation water filters do not get rid of pathogens. Others like RO water purifiers and UV filters effectively make the water free of disease-causing agents.
When you carefully weigh the pros and cons of boiling versus filtering tap water, you will realize that filtering water is more beneficial than boiling water. The shortcomings experienced with filtering water can easily be overcome by using a different water filtering technology or using different water filters in different stages of filtration.