10
VIII CLEANING PROCEDURES
WHEN TO CLEAN
Cleaning is required when the quality and/or quantity of water produced falls off by 10% or more from the
original readings at the time of installation. Several conditions can cause a reduction in water quality
and/or water production. The following should be checked first to see if they are causing the problem
before considering cleaning.
•
Water pressure change
•
Temperature change
•
TDS level increase
•
Prefilters plugged
•
High pH level
WATER PRESSURE
These RO units are designed to operate at pressures between 130 and 190 PSI, any change up or
down; adjustments must be made.
TEMPERATURE
These RO units are tested with water at 25 degrees C and 250 MG/L TDS. Lower water
temperature will result in less water passing through the membrane. Higher water temperature
results in more water passing through the membrane.
As a rule, at a given pressure and TDS level, for each 1-degree change in water temperature the
change in water production is approximately 2%. Thus, if the water temperature is 5 degrees C,
the amount of water produced will be 40% less than at 25 degrees C.
TDS AND REJECTION RATE
As the TDS (total dissolved Solids) level climbs, the amount of water passing through the RO
membrane decreases. If the TDS level has climbed since the time of installation, the unit will
produce less water.
Check the TDS level of the feedwater and compare it with the TDS level at time of installation.
If the TDS levels have climbed, the rejection rate will have to be increased to reduce the TDS
level build up within the membrane.
PREFILTERS
Five Micron (NAK-139 BP)
A dirty prefilter can reduce the amount of water and the pressure going to the RO unit. If the
cartridge appears dirty and/or the differential pressure exceeds 10 PSI it should be cleaned or
replaced (model wars-5). On extremely dirty water, a larger prefilter may be needed.
Activated Carbon (CAK-139 BP)
The activated carbon prefilters are used to reduce volatile organic substances
and chlorine. They should be changed every 3 months or sooner if chlorine is detected after the
activated carbon cartridges.
Summary of Contents for CAK Series
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