| Reverse Osmosis-Great System If You Need One-But Do You? |
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| Food and Drink - Ethnic Foods |
| Written by David Eastham |
| Tuesday, 18 November 2008 08:15 |
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It's true, if you have salty or brackish water with a lot of inorganic material in it, you will be pleased with anything that will clean it up and reverse osmosis water units will. But, if you are getting your water from a municipal water system or a chlorinated well; I've got good news for you. There are much cheaper selective filtration systems you can get that will do a better job, and produce healthier water, than reverse osmosis systemes. In this article we will look at each system and how they work, and you can decide what's best for you.
It's true, if you have salty or brackish water with a lot of inorganic material in it, you will be pleased with anything that will clean it up and reverse osmosis water units will. But, if you are getting your water from a municipal water system or a chlorinated well; I've got good news for you. There are much cheaper selective filtration systems you can get that will do a better job, and produce healthier water, than reverse osmosis systemes. In this article we will look at each system and how they work, and you can decide what's best for you. 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. Hard water or water with excessive minerals is a problem in many water supplies and the fact that RO systems remove these minerals is another plus for these systems. However, it also has been found to cause another problem. 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. Health experts also tell us that cancer cells seem to grow only in a slightly acidic environment and, for that reason, they feels there is a long-term health risk associated with drinking demineralized water. Reverse osmosis will not remove contaminants such as drugs, chlorine, THMs (chlorine byproducts-carcenogens), herbicides, pesticides, SOCs, etc. because molecules are very small and will pass through the membrane. The EPA recognizes activated charcoal as the best filter for removing these compounds and you must be certain you have one if you go the RO route. Since the pores in the membrane are so tiny, you must have sufficient water pressure to force the water through the system and this may necessitate a booster pump be added. 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. As you can see, these systems with their filters, storage tanks, and, perhaps, an additional pump are sizeable and, as you might imagine, they are relatively expensive, somewhat difficult to install and subject to extra operating and maintenance costs. 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. Now, let's look at an alternative to reverses osmosis, the selective (or multi-stage) filtration system. 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. What about the filter resin that covers the surface of the adsorption area? Heavy metals, such as mercury or lead, have positively charged ions. When they pass over the chemically charged resin they are drawn to the resin as if they were magnets. Other metals, like calcium or potassium, pass by unaffected. The systems are very compact and uncomplicated looking. They clean the water and leave the good minerals, and they are very quick, so complicated storage tanks, booster pumps, operating electricity, etc. are not needed. And, without all that "stuff", if they are hooked up right, they produce a steady source of good water with very little maintenance. Be sure you consult a technical representative for any system you are considering if the water you want to treat has extreme problems. They folks will invariably have a good solution. Also, please note that selective filtration is not designed to treat salt water. About the Author: David Eastham has done extensive research on such subjects as reverse osmosis to discover the best way to provide good, clean drinking water. Here are his picks as the best dollar for dollar buys, and the best products overall, in home water filtration technology. |