Tap water is widely consumed in modernized nations, but the truth is that it's often not as safe to drink or cook with as so many people assume and as so many governments insist.

As a matter of fact, unsafe tap water is a growing, and in some areas, chronic problem, which is why so many people turn now to bottled spring water (which all too many times is fake). Asthma, cancer, and cognitive damage have all been linked to the consumption of unsafe tap water through numerous studies.

Nobody is deliberately allowing tap water to be dangerous, but ignorance seems to be widespread. City and town water systems often use powerful synthetic chemical treatments to attempt to purify their water, but these chemicals can of course have negative side effects and be unsafe in their own right. What's more, these places' water delivery systems are often old and corroded, letting substances like rust or lead particles into the water. The most often used (although no longer recommended) municipal tap water purifying chemical is chlorine, but bacteria keep evolving to resist it and it has itself been linked to cancer.

In the United States, the Environmental Protection Agency supposedly sets safe consumption level standards for all possible water contaminants and if a water supply meets these standards the agency approves it. But these safety standards are rarely set at "zero", so the government allows all sorts of substances to be drunk.

Clearly, bureaucracies aren't good enough at giving sufficient water consumption protection to citizens, and so citizens need to respond by using water purification systems in their own homes or businesses.

Different water purification systems come with different filters.

Carbon filters are usually placed right onto your tap, and as the water is forced to pass through them they cause many impurities to "stick" to them as they form an oily barrier between themselves and the water, which now passes through without them. Ceramic filters work in a similar way and are particularly designed to destroy living pathogens such as viruses and bacteria. The other typically used filters are more complex and fit in at other places in your water delivery system.

There are jug filters, which almost always use granular activated carbon (GAC) filters and filter the water as it is poured out of their container.

Sediment filters are attached to your water tanks and are used to removed dirt and grime from water supplies that are so filthy that the filth is visible.

KDF filters can be added in with a carbon filter. The purpose of the KDF filter is to removed heavy metals from the water supply.

If you use a distiller filter, water flows directly to it where it gets heated, contained, evaporated, and then passed on to your tap. The distiller filter is used to removed salt.

De-ionization filters are wall-mounted cylinders that receive the water before it reaches the tap. These use hydrogen ions to take out heavy metals from water, and they are high maintenance.

Reverse osmosis filters also receive and filter out water directly from your water tanks, and they are used in homes or offices where the water pressure exceeds 40 psi because they work by way of intense forcing of the water through their membranes.