Metro Pure Water
Most providers hang a single sediment filter on the back of an ice machine and call the job done. We put five stages in front of drinking water and ice alike. Here is what each one is for.
Stage one: ten micron sediment
Dirt, sand, grit, rust and pipe corrosion. For scale, a human hair is fifty to seventy five microns across. A competitor’s twenty five micron cartridge stops at particles you can still see.
Stage two: pre carbon
Organic contaminants, chlorine and chloramines. This is the stage that takes out the swimming pool smell.
Stage three: reverse osmosis
The membrane filters to one ten thousandth of a micron and removes roughly 98.5 percent of known contaminants, including dissolved salts. It is the same process used to make seawater drinkable.
Stage four: mineral, optional
Raises pH and puts minerals back. Reverse osmosis is thorough enough that some people find the result tastes flat, and this stage fixes that.
Stage five: post carbon polish
Coconut shell carbon, catching any remaining taste or odor on the way to the tap.
This is not about distrusting the city
The EPA regulates municipal water at the source and the FDA regulates drinking water. Water can leave the treatment plant clean and still travel through a hundred years of old pipe before it reaches your building. Filtration is about everything that happens between the plant and the tap.