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Old 06-05-2007, 03:13 PM
Senior MemberCaptains Club MemberPLEDGER
Join Date: Jun 2005
Location: Naples, FL
Posts: 3,914
Default RE: Need info On Reverse Osmosis

thresher15 - 6/5/2007 8:32 AM

Does anyone know much about RO systems? I'm talking about the kind that mount under the sink with a single tap, not a whole house one. I had a plumber install one at my last house and want to get one for this house. Mighty expensive though. So Home Depot has a GE one for about 1/3 of the price. 2.5 gallon tank, 10 gallons per day. It only has 2 RO filters and a carbon filter where the last one I had had 3 RO filtersand a carbon filter. Comes with a data sheet that says it removes 98% of this and 98.4% of that etc. but who can tell me what I should look for in this type system?

I have a 200 gallon aquarium that I do RO/DI water changes of about 55 gallons a week. Since you don't need the de-ionization stage for drinking water (makes water taste funny/dry) you can get by with just about any RO unit. The magic is in the membrane, only nearly pure water will pass through the membrane, the rest gets discharged down the drain. Prior to the this membrane the filter will usually have a sediment filter (usually 1 micron) which removes large particles, then it goes through a charcoal filter. The charcoal filter removes much of the clorine present prior to going through the membrane. All the water that gets past the membrane will collect in your your drinking water tank. How much pure water a day do you need to make is the real question. The membranes determine how much water a day you make. My aquarium RO/DI unit (Kent Marine) can make 100 gallons a day. (my water is collected in a sump below my tank and takes about half a day to fill up) For drinking water you can use a much more inexpensive 10 or 20 gallons a day membrane. Membranes need to be replaced every x amount of gallons, your membrane packaging will say how often to replace. The sediment and charcoal filters also need to be replaced at certain schedules. My unit cost about $400.00 and the yearly filter replacements cost about another $200. I've seen the drinking water filters at Lowes and Home Depot for much less. I think most of the drinking water tanks are 3-5 gallons. Installation is very simple, but water leaks and water damage can be quite expensive. You might want a plumber to install.
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