A Review of the Best Whole House Water Purification Systems
The idea behind whole house water purification is to place a filter system on the cold water supply as soon as possible after it enters your home. This way you will have contaminant-free water in your kitchen, the showers, all over, even for the dishwasher and for washing clothes. In this article we will discuss what needs to be removed from your water, how these systems clean it out and what system would be the best for you.
1. What should you expect for a home water purifier?
You should expect any good house water purifier to filter out at least 99 percent of all the dangerous contaminants and leave you with good, healthy water to drink, cook with and bathe in. Poisons like chlorine and the over 600 carcinogenic byproducts of chlorine, lead, weed killers, sex hormones, antibiotics, chemotherapy medicines, etc., all of which have been found in water supplies.
2. How do these systems remove the pollutants?
You need to know home water purifiers are not just one big filter. They are made up of a number of filters, each of which has an assigned task. The first filter the water encounters is called a pre-filter and its job is to clean out any large globs like dirt, debris from pipes, etc. that could harm later filters.
When it comes to removing the harmful chemicals compounds nothing is better at the job than activated charcoal. The Environmental Protection Agency has long recognized activated carbon as the best technology for removing the chemical bad guys, so, a carbon filter is likely to be next.
In order to remove the remaining pollutants the third step usually will involve either distillation, reverse osmosis, or what is referred to as selective filtration or multi-stage filtration utilizing an ion exchange process.
With distillation, water is heated until it vaporizes and the steam is transferred to a cooling chamber, there it condenses back to the liquid state. Any bacteria that survived the chlorine are killed and minerals like lead, calcium, magnesium, etc. are all removed. Distillation, however, cannot handle organic chemicals which is why it must be used together with a carbon filter.
The electricity used in the process of distillation creates a high energy cost and these units are very slow, producing less than four gallons a day of filtered water.
Reverse osmosis units push water against a semi-permeable membrane with very fine pores, the size of water molecules. The process rejects certain contaminants, minerals, and even a large part of the water itself. Most SOCs, such as herbicides and pesticides, are smaller, molecularly, than water and will pass through the membrane and will not be filtered out. That is why these systems must be used in combination with a carbon filter.
Reverse osmosis systems waste as much, or more, water than they produce, and they are slow producers as well, producing one four or five gallons of water a day. If the home water is inadequate, a booster pump may be required and, in order to accumulate a volume of water, special storage tanks are needed. Component cost, waste and operating cost make the complete systems about equal in cost with the distillation units.
Since both of these systems remove all minerals from the water, including healthy trace minerals the body needs, a problem is created. Water in this condition becomes a little acidic and, after we drink it, it will have a natural tendency to return to a neutral pH. It does that by pulling calcium from our body. For this reason, some medical professionals feel this water is unhealthy to drink.
The third system starts with the adsorptive power of activated charcoal and it is blended with a chemically charged resin to create a very different, but highly effective, filter media.
This blend is compressed into a solid carbon block in which contaminants bond either chemically or physically, like little magnets, to the adsorptive surface. Minerals like lead or mercury are then removed by an ion exchange that chemically attaches them to the resin. Chlorine, herbicides and other chemicals physically attach to the charcoal through adsorption. This compressed carbon also has a tiny, sub-micron pore structure that will remove any chlorine-resistant cysts like Cryptosporidium and Giardia.
Brackish or salty water cannot be handled by selective filtration systems. However, this would only be an issue with about 5 percent of households in the U.S.
Big pluses with these systems are their initial cost and their low operating costs. They process water very quickly, with a very small loss of water pressure, so they don’t require booster pumps or storage tanks.
3. Of the three systems, which one should you choose?
Reverse osmosis is the only way to go if you a fighting a salt water problem. They are not the cheapest systems to own and operate, but they are by far the best solution for brackish water.
Barring a salt water problem, I don’t think you can beat selective filtration for the quality of water produced, or for the price. The unit cost is the lowest and they should operate almost maintenance free, only needing a periodic filter change.