The water treatment industry has done a disservice to its customers.
For years, the exact benefits of water equipment have been vaguely described. Even naming conventions are confusing. The same equipment can go by different names like water softener, water conditioner, or even water refiner.
This doesn’t even take into consideration the “magical systems” that use magnets, blenders, or laser beams to perform some kind of result that can’t be measured, verified, or certified.
This can frustrate consumers. This can also lead to statements like:
“I have pure water – I have a softener”, “We have a purifier in our refrigerator”, or “Our water is so bad, we’ll always have some rust – we do have an iron filter”.
So the purpose of this article is to give a high level review of water softeners, water filters, and water purifiers. Enjoy!
By definition, soft water contains less than 1 grain per gallon (gpg) of hardness (measured as CaCO3), which is essentially dissolved rock. Water softeners use small plastic beads called “resin” that simultaneously attract hardness while releasing sodium ions into the water.
This is the definition of ion exchange: you are trading/exchanging a hard mineral (calcium carbonate) for a soft mineral (sodium).
Water softeners can also remove small amounts of dissolved iron and manganese, but these minerals can be problematic as resin was really not designed to remove these.
Once these beads are coated with hard minerals, the system must regenerate the resin beads with additional sodium so the system can resume functioning.
So that’s it. Water softeners take out hard “nuisance” minerals that damage your glassware, plumbing, and appliances.
In the filter world, there are different formats: under-sink/point-of-use (POU), and whole-house/point-of-entry (POE). There are many, many different types of specialized filter medias used for specific problems like arsenic, or nitrates. In an effort to keep it simple, we are going to look at the three most common filter types:
By far the most common filters on the market, carbon can be made from coconut shells, coal, or even wood. These systems include the faucet-mount and refrigerator filters that line hardware store aisles.
Carbon filters cannot take out minerals, metals, or salts. They are, however, excellent at removing organic chemicals and disinfectants like chlorine.
Carbon works like a sponge. The surface of carbon has millions of little pores that adsorb these organic-based contaminants. The bigger the filter, the slower the water flow, the better the filtration. When measuring overall water quality, carbon filter will give you a 10-30% improvement.
Sediment filters remove dirt and large debris from the water. They are rated by the smallest size of particle they can trap. 20-50 micron is usually adequate for dirt and debris, while certain applications require much finer filtration down to 1 micron.
Sediment filters can trap a VERY LIMITED amount of oxidized iron, but will quickly load up and eventually dump all the iron back into the water.
Iron Filters are almost exclusively used as point-of-entry systems that treat all the water for a home or business. These filter systems use a 2-step process:
Step One: an oxidant like air, chlorine, hydrogen peroxide, or ozone is added to the water to cause undesirable minerals to precipitate and physically settle out of the water.
Step Two: a filter vessel mechanically strains oxidized iron, manganese, and hydrogen sulfide out of the water – much like pouring raviolis through a colander!
You must be careful, as you can only push water through a filter so fast. If you exceed a system’s flow rate, iron/odor will bleed through, and the water will come out unfiltered! A majority of the problems we see come from undersized iron filters.
Ah, the best for last. Water is often referred to as “Nature’s Perfect Solvent”. As that lowly water drop travelled down through the atmosphere, onto land, and eventually down through the Earth’s crust, it dissolved a number of non-water friends.
Purifiers are tasked with returning the water drop back to its roots: Hydrogen and Oxygen.
While there are Nano and Ultra Filters on the market, the most popular would be the Hyper Filter, better known as REVERSE OSMOSIS!
While Reverse Osmosis (R.O.) systems also use a series of carbon and sediment filters, the most important component would have to be the membrane element.
A high quality residential or commercial membrane will separate salt and metal ions down to .0001 microns in size. During this purification process, water is diverted into two separate streams:
Pure water, also known as the permeate, is held in a sealed container until it is used.
Non-water, also known as the concentrate, is sent down the drain – waiting to one day re-connect with its good friend the water drop.
When combined with other filters, these systems can remove sediment, organics, salts, and heavy metals. You can easily get 90-99% pure water!
In the past, reverse osmosis purification systems have only been used for drinking water. New technology has emerged that provides a cost effective solution to whole-house/whole-business purification. Many homeowners and restaurants in the Twin Cities have installed this system, and the results have been nothing short of amazing. The cleaner the water, the better everything works.
Here’s a quick re-cap:
Water SoftenersWater FiltersWater Purifiers
Exchange hard minerals for salt, thereby protecting a home or business from damage.
Remove dirt, debris, and organic chemicals. Also improve taste and smell.
Remove dirt, debris, organic, inorganic, salts, and minerals***
Remove chemicals, bacteria, or improve taste/smell.
Remove hard minerals, salts, metals, or bacteria.
Remove hard minerals******There is currently one membrane material on the market designed to remove hard minerals.