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Residential RO Systems/Membranes Questions

Can I use Copper Tubing for the RO Product Water?

No. Due to RO product water being very pure, it can leach the minerals from copper tubing which will cause a metallic taste in the water or ice, and cause the copper tubing to develop pinhole leaks over time.

How Far Can A Line Be Run From the RO System?

If using 1/4" Poly tubing: Approximately 20-25 Feet.
Use 3/8" Poly tubing for longer distances.

Tubing for RO product water should always be POLY tubing, not copper.

What does each filter do in a residential RO System?

Our AAA series residential reverse osmosis systems are 5-stage systems.

Stage 1 is a 5 Micron Sediment filter, to remove suspended solids such as dirt, dust and rust from the water. This helps to extend the life of the membrane and filters downstream by removing any particles which can clog and damage them.

Stage 2 & 3 are carbon block filters to remove chlorine, taste and odor from the water. It is important to have these upstream from the RO membrane in a system, as they remove the chlorine which will damage the membrane if it comes into contact.

Stage 4 is the RO (reverse osmosis) Membrane which removes 98% of the total dissolved solids in the water. This is where the purification takes place.

Stage 5 is a GAC (granular activated carbon) "polishing filter" which the water passes through right before going to the faucet. This helps to improve the flavor of the water, and to remove any taste or odor that the water may have developed while in the storage tank.

Do I need a booster pump for my residential RO system?

Water pressure is necessary to force the water through the membrane and to flush the rejected solids out of the element, and is directly related to production and quality of filtration. Low pressure can result in low production, low rejection, and premature fouling of the membrane.

The ideal pressure for an RO System is approximately 60 PSI. Generally anything between 40 PSI and 60 PSI is considered acceptable. If your water pressure is below 40 PSI, a booster pump is required to boost the water pressure.

Can I use the RO water for my icemaker or refrigerator?

Yes. The RO treated water can be run to an icemaker. This can be done by installing a 1/4" tee in the line between the final polishing filter and the faucet. 1/4" POLY tubing should be run to the icemaker.

All tubing for RO water should be POLY tubing. Copper tubing should not be used.

Why am I getting very little output from my RO?

Please check the following:

  • If the water pressure is below 40 psi, a booster pump may be necessary.
  • If the water pressure is above 40 psi, first try to re-tap the tap supply
    line. This can be done by tightening the self-piercing valve clockwise until
    it is fully turned, then turn it counterclockwise until it stops. There should
    open enough space in the line for proper water flow.
  • Straighten or repair the tubing
  • Check that pre-filters are not clogged. If they are, they will need to be
    replaced. If membrane is fouled, it will need to be replaced.

How often do I need to change my filters?

There is no definite answer to this question, as the feed water conditions
and system maintenance will affect filter life.  Below is a guideline:
Sediment and Carbon Prefilters: Every 3-6 Months
Carbon Post Filter: Every 3-6 Months

Membrane Element: Every 12 Months

Why is there no water in my storage tank?

Possible Cause Remedy
Filter cartridges have failed Replace filter cartridges as indicated
Cartridges upside down Install carbon block filter right side up as indicated on the filter.
No pressure in storage tank Check pressure with gauge.  Refill or reduce pressure to max. 8 psi.
Automatic shut-off malfunctioning Check lines to valve for correct hook-up and check for water running into drain.  Replace if necessary
Kinked lines Straighten lines if necessary

How do I check and refill the pressure in my residential storage tank?

The tank should be empty before checking the pressure.  First open the faucet to drain the tank as far as it will go by itself.  Remove the plastic on the front of the tank to expose the air valve.  Using a bicycle tire pump, fill up the tank only until the water begins to flow out.  Do not over pump the tank or you may ruin the bladder.  Keep doing this until you are sure all of the water is out of the tank.

Once the tank is empty, test the pressure using a tire pressure gauge.  This should be at approximately 7-8 psi.  If the pressure is low, use a bicycle tire pump to fill with more air until the pressure reaches a maximum of 8psi.

Why is the water backing up to the air gap faucet?

Possible Cause Remedy
Line is clogged Clean out the line
Line is too long Must be as short and straight as possible
Drain is clogged Disconnect the drain line and clean out with probe or by flushing

 Why is my faucet spout dripping?

Possible Cause: The hande is sticking or worn.
Remedy: Replace the faucet.

Why is Water Leaking from the Filter Housings?

Possible Cause Remedy
Filter sumps are loose Retighten the filter sumps to the caps
Burr on edge of filter housing Remove burr with emory cloth or sand paper
O-Ring in filter bowl is missing, damaged, or not seated properly Replace or position correction

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All Content on this site is  intended for informational purposes for experienced water treatment professionals only.  Applied Membranes, Inc. does not assume any liability for any damages caused by the misapplication or misinterpretation of any of the information contained on this website.
Applied Membranes, Inc. 2007