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General Precautions
WARNING: The RO-3000 and RO-3500 systems contain a replaceable
membrane critical to the efficiency of the system. Replacement of
the reverse osmosis membrane should be with one of identical
specifications, as defined by the manufacturer, to assure the same
efficiency and contaminant reduction performance.
WARNING: The RO-3000 and RO-3500 systems contain a replaceable
membrane, critical for the effective reduction of total dissolved
solids. Product water should be tested periodically to verify that
the system is working properly.
WARNING: The RO-3500 is acceptable for treatment of influent concentrations
of no more than 27 mg/L nitrate and 3 mg/L nitrite in combination
measured as N and is certified for nitrate/nitrite reduction only for
water supplies with a pressure of 40 psig (280 kPa) or greater.
WARNING: The RO-3500 shall only be used for arsenic reduction on
chlorinated water supplies containing detectable residual free
chlorine at the system inlet. Water systems using an in-line
chlorinator should provide a one-minute chlorine contact time
before the RO system.
WARNING: The Reverse Osmosis (RO) system will not protect against disease-
causing bacteria or remove naturally-occurring harmless bacteria.
CAUTION: The RO-3000 and RO-3500 systems must be protected against
freezing which can cause the filter housing to crack and water
leakage.
CAUTION: Because of the product's limited service life and to prevent costly
repairs or possible water damage, we strongly recommend that
the filter housings be replaced every ten years. If your housing has
been in use for longer than this period, it should be replaced
immediately.
Date the bottom of any new filter housing to recommend the next
replacement date.
CAUTION: Do not use Plumber’s Putty in the installation of this product as it
may cause cracking of the filter housing threads.
NOTE:
• Your water must be within required limits for satisfactory operation. If not,
your membrane life may be shortened and your warranty will be voided (see
Operating Specifications on page 1).
• Install on cold water line only.
• Make certain that installation complies with all state and local laws and
regulations.
• The reverse osmosis membrane and replacement cartridges included with
this system have limited service lives. Changes in taste, odor, and color of
the filtered water indicate that the cartridge(s) and/or membrane should be
replaced (see Maintenance on page 10). On the monitored model (RO-3500)
the green light indicates optimum performance while the amber light
indicates that the membrane is in need of changing.
• During extended periods of non-use (such as during a vacation), remove the
membrane from the membrane housing and place it in a sealed plastic bag.
Store membrane in refrigerator for future use. DO NOT FREEZE.
• If system stands for more than 2 to 3 days without being used, the storage
tank should be emptied.
Membrane Precautions
CAUTION: Chlorine will destroy the Reverse Osmosis membrane. If you use
these RO systems with a chlorinated or periodically-chlorinated
water supply, it is ABSOLUTELY NECESSARY to use a carbon pre-
filter (such as the USL-NCR cartridge, included with the system).
This carbon pre-filter should be changed at least every 4 months
to avoid chlorine breakthrough. See warranty for disclaimers and
limitations that apply to the RO membrane.
NOTE: To make sure no chlorine is present in the water that reaches the
membrane, you may want to use a chlorine test kit to check the
reject water that flows from the membrane to the drain. No chlo-
rine should be detected.
How Reverse Osmosis Works
The Pentek RO-3000 and RO-3500 use a semi-permeable membrane to reduce
dissolved salts, improving the taste and odor of your water. The RO membrane is
made of multiple layers of micron-thin film wound around a hollow center core.
Water molecules can pass through the membrane, while dissolved salts are
rejected. The Pentek RO-3000 and RO-3500 systems feature triple-filter action.
Your household water supply is pre-filtered to reduce dirt and chlorine that may
foul the membrane. The RO membrane separates this pre-filtered water into
PRODUCT WATER and REJECT WATER. Your household water pressure forces
the product water through the membrane and into the storage tank. Dissolved
salts cannot pass through the membrane and are sent to the drain as reject
water. When you open the RO faucet, product water is drawn from the storage
tank through a post-polishing filter. The post-polishing filter takes out any
remaining taste or odor in the water and provides you and your family with
cleaner, great-tasting water.
The RO-3000 and RO-3500 systems also feature an auto shut-off valve, which
shuts off the system once the pressure in the storage tank reaches 2/3 of the
incoming water pressure (your household water pressure). When you open the
faucet to draw water from the storage tank, the pressure inside the tank drops
and the auto shut-off valve opens. The system then begins to operate,
replenishing the water you took from the storage tank. For each gallon of water
produced, 7 gallons are discharged as reject water. The storage tank can hold
up to 3.2 gallons of water at a time, more than enough for the average family's
drinking and cooking needs.
When used under operating conditions specified on page 1 of the manual, your
Reverse Osmosis membranes should last 12-24 months.
NOTE: The RO-3500 unit will indicate a need for a membrane change with
an amber light, see Light Indicator Readings on page 9 for details.
The precise life span of your system's membrane will depend on the quality of
the water entering the system and the frequency with which you use it. Frequent
use prevents the dissolved salts from building up on the membrane as scale. The
more water the system is required to produce, the longer the membrane will last.
You may wish to find a variety of uses for your system in order to prolong the life
of the membrane. The life of the membrane will also depend upon the regularity
with which you replace the pre-filter cartridge in the system.
