Aqua-Pure APPM150 - Manual (Page 18)

4-1
Section 4: BACKWASHING INSTRUCTIONS
Periodic BACKWASHING of the APPM Series Iron Reduction Filtration System bed is required to fl ush out the entrapped iron that has accumulated. This pro-
cedure is performed automatically at 1:00 a.m. for a period of approximately ten (10) minutes, and will not interfere with a softener regeneration which is
usually set for 2:00 a.m.
TO SET BACKWASH FREQUENCY FOR NORMAL HOUSEHOLD APPLICATIONS:
To determine and set BACKWASH FREQUENCY, follow these instructions:
1) Select BACKWASHING FREQUENCY SCHEDULE corresponding to your model (please see next page).
2) Locate box intersected by number of persons in your family and iron concentration of water (if iron concentration is between two numbers in SCHEDULE,
use higher number.)
3) Number in box represents number of times, in 12 days, timer should be set to regenerate. Refer to HOW TO SET TIME CONTROL, page 3-9 to set timer.
EXAMPLE: You have model APPM150, 4 in family and 8 ppm iron. Refer to SCHEDULE for model APPM150 and locate box intersected by 4 in family and 8 ppm
iron. The fi gure “2” in box indicates a BACKWASH frequency of two times per 12 days (if a “1”, “3”, “4”, “6”, or “12” were in box, frequencies of once, three,
four, six and twelve times per twelve days, respectively, would be indicated.)
IMPORTANT NOTE IMPORTANT NOTE
The BACKWASHING FREQUENCY SCHEDULES are based on average water consumption rates and are merely guides. They are NOT intended to be used if
water used by outside spigots, a swimming pool, geothermal heat pump, or other high water usage devices or activities are to be treated by the APPM Series
Iron Reduction Filtration System. If your application includes any of these, and you have already determined your model APPM Series Iron Reduction Filtration
System is capable of handling the fl ow rates involved, refer to the next paragraph for instructions on setting BACKWASH FREQUENCY.
TO SET BACKWASH FREQUENCY FOR NON-STANDARD HOUSEHOLD APPLICATIONS:
If your fi lter is to be used for reasons covered above, the BACKWASHING FREQUENCY SCHEDULE is not applicable, determine the backwashing frequency as
follows:
1) Estimate DAILY IRON REDUCTION by multiplying iron concentration by estimated daily water consumption (use 75 gals. per person per day for normal
household applications):
Est. Daily Water Usage ______ x Iron Concentration _____ = Daily Iron Reduction ____________
(gals.) (ppm) (ppm - gals.)
2) Calculate BACKWASH FREQUENCY by inserting DAILY IRON REDUCTION from above into following formula (refer to specifi cations for IRON REDUCTION
CAPACITY of your model):
Iron Reduction Capacity of Your Model _________ ÷ Daily Iron Reduction _________ = Backwash Frequency _________
(ppm-gals) (ppm-gals.) (days)
The resulting number of days between backwashings should be converted to the nearest MORE FREQUENT obtainable timer setting (i.e., a calculated fre-
quency of 3.7 days should be converted to a 3 day interval, and a 9.2 frequency to a 6 day interval). It is not possible, however, to set the timer less frequently
than once every twelve (12) days.
If your water contains a high iron concentration, manganese, tannins or hydrogen sulfi de it may be advisable to increase the backwash frequency up to daily,
if necessary. It should be noted, however, that increasing the frequency or duration of backwashing WILL NOT overcome an insuffi cient pumping rate.