The GE Merlin

The GE Merlin
Posted in: Reverse Osmosis
By Mark Timmons
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The GE Merlin

[caption id="attachment_77" align="aligncenter" width="108" caption="The GE Merlin RO System"][/caption]

One of the most popular products in the water treatment business is the GE Merlin 700 Gallon Per Day Reverse Osmosis System.  It delivers nearly a half gallon a minute under ideal conditions.  Consumers hear that it is "tankless" and assume it is better than other "tank-type" RO's and is the latest and greatest in reverse osmosis technology.  While it is an amazing piece of equipment, it does have issues.  First of all, let's talk about its' good points.
  1. It makes lots of water and does it economically, so if you brew beer, do reef-keeping, have a salt water aquarium, greenhouse of do hydroponics, the Merlin is hard to beat, especially if you need hundreds of gallons of water a day.
  2. The more you use a Merlin, the better the water is.
  3. The initial cost is very low and it is downright impossible to find any reverse osmosis system that can produce this much water at such a low price.
Now, the drawbacks of a Merlin:
  1. If you use only a few gallons of water a day, the odds are that the water quality will be wretched unless you use a "flush tank," because of TDS Creep.  The flush tank surrounds the GE Merlin Membranes with RO water to prevent the TDS creep, but it also causes the Merlin to use a lot more water (it will waste 4-5 gallons each time it fills the flush tank, which is every time you turn on the faucet - If you get a drink 10 times a day, you will waste about 50 gallons of water for those 10 glasses!).
  2. The Merlin has problems shutting off.  In other words, after you have stopped using water, and the Merlin should shut-down, it doesn't!  Instead, it just runs to drain and may waste hundreds of gallons of water a day.  We have an inordinate amount of Merlins that are sent back because of this.
  3. It sounds like a "freight train" when it is making water!
Here's an actual case study with a GE Merlin.  We installed a GE Merlin under the kitchen sink for a man in Brownsburg, Indiana, which has a TDS (total dissolved solids) level of 520.  He kept complaining of "cloudy ice cubes."  So, we went to his home after the RO had sat unused all day.  We tested the first glass of water and it was 415 PPM.  Here are the rest of the results:
  • After 1 minute -   346 PPM
  • After 2 minutes - 278 PPM
  • After 3 Minutes - 191 PPM
  • After 4 Minutes -   96 PPM
  • After 5 Minutes -   19 PPM (Pretty good water, but who wants to wait 5 minutes for a glass?)
Now, this could be solved by a "flush tank," but in this case, the homeowner said "Why do that?"  So, we put in a permeate pump RO system (which delivers the same amount of pressure out the faucet as you have coming in), which always delivers less than 20 PPM, with better pressure and much less waste water.  Another thing to think about is that the GE Merlin Membranes cost about $200.00 to replace, while you can buy a membrane for the permeate pump RO for less than $30.00.
  • More Pressure
  • Less Waste
  • Better Water Quality
  • Lower Operational Costs
What's not to like?  That's why I have a (non-electric) permeate pump RO in my house. Now, we also find out that GE or Pentair is going to discontinue the Merlin and introduce a new and improved Merlin.  Yes, product failure is part of the reason they are introducing it, but the main reason is that they want to eliminate Internet sales of this product and are only going to give it to a limited number of distributors, who won't sell it on the WEB.  They want to line their distributors pockets with money while sticking it to the consumer... again! Necessity is the mother of Invention.  Watch and see why this will be a mistake for Pentair.
November 11, 2009
Comments
Joe
March 19, 2010 at 11:55 AM
Maybe some of the reason that the manufacturers are going to control the distribution is to prevent people from installing the system on the wrong application. I'm sure that the folks at GE/Pentair probably get tired of fielding complaints from internet consumers about things like TDS creep, noise levels etc. All the issues with bad application of the product are surely giving the product a bad reputation. Professional water treatment dealers will likely be more responsible about the applications they put these systems on because they will be the ones responsible for the follow up service.
Pete
March 29, 2010 at 10:29 AM
Can you tell me how much waste water is produce for every litre of pure water gained Many thanks Pete
mark
April 12, 2010 at 1:34 PM
Joe, I cannot speak to what other companies do, but at US Water we have very good customer support and what is interesting, is that we have MORE (not less) problems from dealer than the end user. I think the end user has "more skin in the game."
mark
April 12, 2010 at 1:34 PM
Pete, 3 to 1