I am sure you have gone through hard time in choosing the right water treatment system. Some are just not even "apple to apple" kind of comparison due to its different nature and functions, some are totally different methology, some just do not produce the similar outcome. In order to do that, the best comparison is to compare the end result which is the "Filtered Water" or the "Purified Water". To understand which water treatment system provide the best water filtration, we will need to understand what a system does and does not perform. We are discussing only the water treatment after water has been supplied to by the water work department.

Distillation

This is not equivalent to boiling water where molecules of water did not leave the original container and stay with whatever other molecules originally there. In distillation, water is being heaten up to its boiling point continuously, the evaporate water molecules will be recaptured by cooling down the steam vapor and collect in another clean container. Both method remove bacteria effectively, but distillation remove traces of minerals like iron, calcium, etc (which obviously has higher boiling point) etc by evaporate into air first. However, contaminants having lower boiling point than water like benzene will not be able to screen out.

Advantage:- Effectively remove bacteria and heavy metals.

Disadvantage:- Also remove trace of natural minerals in water and almost everything else other than water.

Reverse Osmosis

We will need to understand what is Osmosis process, where molecules of water migrate naturally from a weaker saline solution to a stronger saline solution, gradually equalizing the saline composition of each solution which is divided by a semi-permeable membrane. Reverse Osmosis, the opposite of natural osmosis process of water in which the molecules of water are being pressurized to go through a semi-permeable membrane from stronger saline solution to weaker side ( any contaminants having molecule size bigger than water will not pass through).

Advantage:- Remove fluoride, chloride and other harmful particles.

Disadvantage:- Also remove trace of minerals like salt, lead, manganese, iron, and calcium. Can not remove chlorine and volatile organic chemicals which are relatively smaller in size. Having to remove alkaline mineral constituents of water, produces acidic water which will strip off calcium in bones and teeth in order to neutralize acidtiy in it.

Water Filter

By the name it means involvement of some filtration medium, physically intercept selected particles from passing through, or chemically transform selected molecule into other form, or even using the combination of both.

Ceramic filter

Ceramic water filters come as a cartridge that fits a normal bench top filter. Some ceramic filters incorporate nano-silver impregnated into a porous ceramic outer shell that can trap bacteria down to as low as .22 of a micron in particle size [1/100,000 of an inch].

Laboratories consider a filtering medium with an effective pore size of .01 micron to .45 micron to be bacteriologically sterile and .45 micron to 1.0 micron to be bacteriologically safe. Re growth of bacteria that becomes trapped either on the outside of the element or in the ceramic's pores is controlled by the silver which, on contact with water, releases small quantities of positively charged metals ions.

However, volatile organic chemicals (VOCs), chlorine and other undesirable odor and taste compounds, will remain in the treated water after ceramic filtering.

These ions are taken into the enzyme system of the bacteria's cell and thereby neutralize it.

Advantage: Effectively remove bacteria

Disadvantage: Flow rate of ceramic water filters are slow. However, the flow rate of the ceramic filter can be improvised by brushing its outer surface under running water. As the top layer of ceramic and contaminants are brushed off and flushed away, a new layer becomes available.

Charcoal Filter

Charcoal water filter derived from coconut husk . This absorbs impurities as the water passes through. This form of filter comprises possibly 95% of those in use domestically. They are simple to install, relatively economical, and depending on micron level, will filter out the most deadly of contaminants, Cryptosporidium and Guardia.Some charcoal filters are enhanced by the use of activated nano-silver, which provides extra antibacterial protection, killing around 650 known types of organisms.

Advantage: Effectively remove most contaminants by absorbing impurities and economical. Minerals in solution can still permeate a charcoal filter. These minerals are essential to health.

Disadvantage: Need to be replaced at the interval of 9 - 12 months (but its cheap and safe). In area where sediment is a problem, the filter will get clogged easily. Installing a pre filter will prolong its life span.