by David Eastham
You cannot beat reverse osmosis water units when it comes to cleaning up water contaminated with salt. In that case they are worth the headaches. However, 95% of us get our water for a city utility company or from a chlorinated well that does not have a salt water problem. For us there is great news! Newer systems, called selective filtration, are simpler to install and use, cost less and produce healthier water than reverse osmosis. We will check out both systems in this article and you can decide.
The RO system works by forcing water against what is called a semi-permeable membrane. The membrane’s pores are so tiny that any object larger than a molecule of water will not pass through it. Often, water molecules cannot get through either and, usually, this water is simply discarded along with any minerals or contaminants that have been screened. In general, these systems reject two or three gallons of water for every filtered gallon produced.
Some people throughout the US are also dealing with excessive minerals in their water and the fact that RO systems remove these minerals is another reason people have liked them. But, too much of a good thing can be bad.
You see, it seems water with no minerals is not good. That makes sense since nowhere on earth does pure water exist naturally. We need trace minerals like calcium and potassium, for example, in order to stay healthy. And, pure H2O is slightly acidic, so, when we drink this water it will try to get back to a neutral state by stealing minerals such as calcium from our teeth, bones or cells. In this case it produces calcium carbonate as its neutralizing element.
Medical professionals also tell us cancer cells appear to always grow in environments which are slightly acidic, so, they think there can be an increased cancer risk for people drinking mineral-free water.
If you do decide on a RO system, be certain it comes with a carbon filter. This is because chlorine, a deadly poison, along with herbicides, pesticides, THMs, SOCs, drugs, etc., are made up of molecules smaller than water’s so they will not be removed by reverse osmosis systems.
If the water pressure in your home is too low, reverse osmosis systemes will require the addition of an inline booster pump in order to operate properly.
Another requirement of these systems is a storage tank, with a diaphragm to maintain pressure, because most RO systems produce less that one gallon of filtered water per hour. At that rate, without a storage tank, you simply wouldn’t have enough clean water for bathing or doing laundry or much of anything else.
By the time you put all the storage tanks, extra pumps (if needed), and filters together you are going to have a good sized unit. Anytime you have a lot of components you are likely going to be dealing with extra initial and operating costs, and maintenance issues.
Anymore, I feel like using a RO system where you could have used selective filtration is like hunting flies with a cannon…they’re clunky, expensive and give a dangerous result.
Selective filtration is also called multi-stage filtration and it is a good alternative to reverse osmosis.
These systems also use activated carbon to clean up any drugs or chemicals that might be in the water, but this carbon is first blended with a chemically charged resin and compressed into a solid block composed of tiny, submicron pores.
It’s interesting that scientists say a solid block of activated carbon, one foot square on each side, has an adsorption area of five square miles! No wonder is does so well with chemicals and it still has plenty of capacity in the tiny pores to clean up chlorine-resistant cysts, like Cryptosporidium and Guardia and any remaining debris.
Why does the adsorption area have the chemically charged resin?
When heavy metal compounds such as mercury or lead come in contact with this resin, their positively charged ions break their bond with water and snap onto the resin like little magnets. Because of the difference in their molecular structure, the lighter metals such as potassium and calcium don’t react and remain in the water.
There you have it, the water is cleaned but it still has its nutritious trace minerals. Selective filtration systems are quick, so there is no need for holding tanks with diaphragms. Nor is there any need for booster pumps, electricity, backwashing, etc., and, if installed correctly, they operate virtually maintenance free.
Should you happen to be dealing with a severe water problem, is always wise to consult with a technical representative for any system you are planning to use. They know their business and can almost always suggest a solution. If you have salty water, you should be aware that selective filtration is not designed to remove salt.
About the Author:
David Eastham has done exhaustive research on such topics as reverse osmosis to discover the best way to get
good, clean drinking water. Follow him for his choices for the best dollar for dollar buys, and
the best products overall, in water filtration technology.