Reverse Osmosis:

Discussion H20: From Tap to Reverse Osmosis

by Josh Day

If you're on city or municipal water, what you're drinking goes through a maze of processing and filtration before it ever reaches your tap. Raw, unclean water enters the system and is then passed through a fibrous bed of either sand, fine gravel, synthetic floss, or a combination of all three. This mechanical filtration removes sediment and some cloudiness. Activated carbon and other substances then leech harmful toxins out of the water in what is known as chemical filtration. A final stage of filtration is biological filtration. Some treatment plants actually run their water through plant life to absorb nitrates and other forms of nitrogen.

A similar occurrence is found in home aquariums. To clean your fish's water, some form of filtration is necessary. The most common is what is known as a hang-on-the-back (HOB) filter. Water is sucked through the intake tube and then pumped through a layer of fine floss to remove visible particles and waste. There is then a layer of activated carbon for chemical filtration. Finally, good bacteria called nitrobacters exist on the filter floss, the gravel, and plants to consume the harmful ammonia and nitrite which is produced from fish waste and uneaten food. Generally, a water treatment plant is a macrocosm of this system.

The city usually adds chlorine or chloramine to the water to eradicate any pollutants outside the treatment center on the water's path to your sink. Chlorine is like a neutron bomb when it comes to killing everything in water. Chloramine is added as a supplement in some municipal areas to add more oomph when distribution systems are known to carry large tracts of bacteria. Both substances eradicate all bacteria. They are also known poisons in larger volumes and quantities.

Home filters remove chlorine through activated carbon and other means. Bottled water also is chlorine and chloramine free.

Now that we've discussed water treatment and basic filtration, let's get down to brass tacks and talk about additional purification. Many filters offer multiple features in purification, ranging from activated carbon, UV light, to reverse osmosis.

• Activated carbon is the most simple means of filtering tap water. As mentioned above, granules of carbon remove harmful substances like chlorine. With systems that utilize carbon there is often a secondary mechanical filtration layer which eliminates sediments from the pipes. Some units often brag of multiple layers of filtration. This could include carbon, floss, or a UV lamp.
• The next step in filtration is a process called KDF (Kinetic Degradation Fluxion). Now, for those of you who are like me and never took a chemistry class in college, here it is in layman terms: KDF uses oxidation and reduction to remove chlorine and other substances from your water that carbon can't touch. Ok, in English, this is basically another form of chemical filtration which is more powerful than carbon. Many home filters a grade or so higher than those that mainly use carbon utilize the KDF system.
• Onto ultraviolet light. UV light fries viruses and bacteria. A UV lamp is placed in the center of a water passage, and the water surges through the tunnel and is exposed to the bacteria-killing light. Though the light looks really neat, unfortunately, it is only really effective at killing living germs and bacteria and does nothing toward other contaminants.
• Deionized water is simply water with all the ions removed... this makes this type of water very hungry, so to speak. Like distilled water which has no trace elements or minerals whatsoever, D/I water actually seeks out its missing ions. This water is largely used for laboratory experiments and saltwater aquariums. It certainly should not be consumed on a long-term basis.
• The creme de la creme of filtration is water purified by reverse osmosis. This process is so powerful that it's been called hyperfiltration. Water is passed through a membrane so fine that it can remove pretty much anything. There are also several stages of pre-filtration, as well as a storage tank for purified water. Obviously, this system is costly and would take up some amount of space... imagine having a miniature treatment plant under your sink!

Many stores offer water purified through reverse osmosis. There are even vending machines that allow you to buy R/O water as cheap as 25 cents a gallon! This is ideal for me because I maintain a nano ten gallon reef aquarium and R/O water is perfect because all the necessary trace elements are added when the salt is mixed.

However, if you're looking for water for you and your family, R/O water may not be your best bet because of the loss of minerals. Contact your local water department or run a google search to see if they have a website. You can obtain a report of your water read-out, usually free of charge. You can find out if your water is fluoridated, as well as see the level of phosphates, nitrates, and other bad things that comes from the plant to your tap.

And if you're really concerned about the water you put in your body, consider purchasing an aquarium pH test kit at a pet store. These are approximately five dollars and can provide you with clues about the water you're drinking. If the water is below 7.0 on the pH scale, it is acidic. If it is above, it is alkaline. Saltwater has a pH of approximately 8.4. Reverse osmosis water generally has a pH of 6. Spring water is supposed to be on the alkaline side due to its dissolved minerals. According to many experts, acidic water is not good for you on a long-term basis and should not be consumed.