24
PEOPLE
IN
FAMILY
IRON CONTENT (PPM)
2
4
6
8
10
12
14
16
18
20
1
1
1
1
1
1
1
1
1
1
1
2
1
1
1
1
1
2
2
2
2
2
3
1
1
1
2
2
2
3
3
3
3
4
1
1
2
2
2
3
3
4
4
4
5
1
1
2
2
3
3
4
4
6
6
6
1
2
2
3
3
4
6
6
6
6
BACKWASHING INSTRUCTIONS
To Calculate Backwash Frequency - Normal Applications
Backwash frequency for households with average water use can be determined using the following guide. The guide cannot be used if the filtered water supplies a swimming
pool, geothermal pump, outside spigots or other high water demand devices or activities. If your application includes any of the foregoing refer to the paragraph on “Special
Applications” below:
1.
Locate the box intersected by the number of people in your family and
the parts per million (ppm) of iron in your water (if your ppm is
between two numbers on the guide, use the higher number).
2.
The number in the box represents how many times your filter has to
backwash in a twelve day schedule.
Replacing Media Bed
The media bed in a neutralizing Model NU filter is slowly dissolved and has to be replaced. The frequency of replacement varies, depending on water quality - consult your dealer
to determine the expected life of your media bed.
NU
- the media bed in a neutralizing filter is slowly dissolved and has to be replaced. The frequency of replacement varies, depending on water quality - consult your dealer to
determine the expected life of your media bed.
TO
- under normal operating conditions the effective life of the filter media is approximately one to three years depending on the water quality, after which, taste and odor
problems may return. When this happens contact your dealer for a replacement media bed.
MM / nextSand
- under normal operating conditions, the media should never need to be replaced. If you experience pressure loss and cannot correct it with a manual regenera-
tion, your media bed may need replacing - contact your dealer.
BM
- Depending on the raw water iron content.
To Calculate Backwash Frequency - Special Applications
To ensure adequate reserve capacity and prevent loss of water pressure between backwashes the figure of 15,000 (not the full 30,000 ppm capacity) is used to calculate backwash
frequency. Determine your backwash frequency as follows:
1.
Estimate daily iron removal requirements using the following calculation:
No. of people in family
x 75 gallons of water per person
+ No. of gallons of water for special use
= No. of gallons of water required per day
x Iron concentration (ppm)
= Daily iron removal requirements (ppm)
2.
Establish backwash frequency using daily iron removal requirements to complete the following calculation:
15,000 iron removal capacity (ppm)
÷ Daily iron removal requirements (ppm)
= No. of backwashes required in 12 day schedule
Example: You have four in the family, 8 ppm of iron and a swimming pool requiring 46 gallons of water per day.
4 People in the family
x 75 Gallons of water per person
300 Gallons of water for family
+ 46 Gallons of water for the pool
346 Gallons of water required per day
x 8 Iron concentration
2,768 Daily iron removal requirements (ppm)
1 5,000 Iron removal capacity (ppm)
÷ 2,768 Daily iron removal requirements (ppm)
5.4 Backwash frequency (days)
The calculation indicates the need to backwash every 5.4 days. The control can only be programmed to backwash at intervals of two, three, four, six and twelve days. The control
would be programmed to the closest more frequent setting i.e. every four days.
