Saturday, June 26, 2010

Reverse Osmosis Maintenance: H2RO

I have had a reverse osmosis system installed in my kitchen since 1995. I love the benefits of tasty drinking water right out of a special tap. These systems require occasional maintenance. This system just required some maintenance so this post covers: replacing the tank, the Filmtec membrane and the Omnipure filter. I had replaced the other two filters about a month ago.

The Location of the 3-Gallon Tank

I chose to store the large tank in the left corner cabinet, rather than directly under the sink in the double doors to free up space needed under the sink.


The Original Water Storage Tank:

The bladder in the middle of the tank had developed a hole and the air charge had apparently escaped, according to a family member who is in the RO business. This made it nearly impossible to get a glass of water, let alone a pitcher of water. The prognosis? This tank needed replacing. I could tell by lifting it. It should have been light. It was full of water even though the RO faucet appeared to be empty.

(Note: The leak was only on the inside of the tank. There was no exterior leak so no damage to the cabinet etc.)


The Replacement Water Storage Tank:

Placed in the same location as the previous tank. I only had to disconnect the plastic nut and tubing and reconnect it to the new one. Easy! I left that other knob alone on the lower portion of the tank. (Once I lifted the tank into this pull-out drawer, I was able to lift it over the edge and into the back corner of the cabinet. The bright blue lever on the top is the "tank shut-off."




The Location of the Filters and Membranes:
Here is a view of my kitchen cabinets. The filters and membranes are stored in the narrow cabinet to the right of the sink and dishwasher, rather than directly under the sink in the double doors. This freed up space needed under the sink.


The Filters and R.O. Membranes:



In addition to the tank, here's two additional items that I replaced. The smaller peach and light blue filter on top is labeled "OmniPure K2333". It notes for "chlorine taste and odor reduction". Note the arrows pointing to the left for the direction of the flow. Pay attention to that arrow when installing.

The other bright blue item is a "Filmtec membrane", model number TW30-1812-36 made by Dow. "The membrane consists of several thin layers or sheets of film that are bonded together and rolled in a spiral configuration around a plastic tube." (according to my RO manual)

According to Dow's website:
FILMTEC™ elements from Dow feature a spiral wound design and are based on the FT30 thin-film composite polyamide membrane, which has long been the industry standard for RO performance. The FILMTEC FT30 membrane consists of three layers: an ultra-thin polyamide barrier layer, a microporous polysulfone interlayer, and a high-strength polyester support web. The FT30 membrane has been continuously updated and refined to provide higher rejection, improved membrane flux, and low fouling performance. Today's FT30 membrane is uniquely uniform in performance and quality, without the taped or glued defects that can cause other membranes to fail.
Sort of a complicated mess of tubing that also runs to the ice maker on the opposite side of the small kitchen. The gray tubing on top goes to the drain in this instance. It has a "Waste Flow Capillary Tube" installed inside of it. This "looks like a piece of clear nylon fishing line held by a piece of red rubber stuck in a plastic insert. The H2RO could not operate without it, since it allows the contaminants to be washed off the surface of the membrane as a slow but steady rate."


Bird's Eye View:
I replaced the small orange and blue Omnipure Carbon Post Filter. The long white tubular container was a bit challenging to open. That is where the new Filmtec membrane goes. (The white cylinder container has a blue "KE" on it in this photo.)


I ended up using the side of a wrench to slip into that embossed section on the cap of the white cylinder. Be sure to not lose the black rubber ring inside. You will reuse it again when you replace the Filmtec membrane and tighten it back up.


I left this portion of the unit out of the cabinet, on the towel for 24 hours to check for leaks. Once I was certain there was nothing dripping, etc. I felt OK to put it back in the cabinet out of sight.

Note: I had also replaced the two filters that go inside the wide blue vertical cylinders. They both measure 4-1/2" x 9-7/8" and fit large heavy duty housings. They are labeled "S" sediment.

The first one, POS5, is for "Fine Rust & Sediment - 5 microns."
The second one, POW30, is for "Medium Filtration Rust & Sediment - 30 microns."

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