- 7 -
open the flushing valve totally. After flushing close the
valve carefully - without power. In operation minimum
three times more brine flows than pure water!
Careful maintenance increases the life time of the
reverse osmosis membrane.
An automatically driven
flushing valve can be mounted to the unit - even after
installation of the mounting board.
Monthly flushing of the unit
To increase the life time of the membrane please flush the
reverse osmosis unit every month for 15 to 30 minutes.
Open the flushing valve totally and prove the water
outflow. If the water do not runs out of the brine tube for
minimum 5 liters per minute check the pre filter(s) or the
water pressure.
After flushing close the flushing valve.
Attention: the
flushing valve do not shut totally! Do not close it
tightly! Otherwise the correct function of the reverse
osmosis unit is not guaranteed.
Maintenance every four month -
change of the pre filter(s)
Check the condition of the pre filter(s)
. Blocked filters
reduces water flow and increases the quality of the pure
water enormously. If the pre filter is not changed for a
long time the membrane can be destroyed.
To check the pre filter shut of the water tap and release the
pressure from the unit (wait for a minute). Unscrew the
housing of the 10" pre filter (9). Take off the filter
cartridge (10) and lock at its color and condition. If the
color is brown, red or black and smells, the cartridge has
to be changed. Therefore put a new filter into the filter
housing and screw the housing at the top. Do not forget
the ring seal.
The combi filter has a normal life time of 6 to 12 months.
If the life time is shorter than 6 month use a score filter
before the combi filter.
Check the water flow.
Therefore you need a measuring cylinder and a watch with
seconds. Start the reverse osmosis unit. After flushing the
flushing valve operated the unit for minimum 10 minutes.
Then fill the pure water into the cylinder. Take the time
after 1 liter pure water. Calculate the water flow with the
formula:
water flow
volume
time
in litre / day
in litre
in minutes
=
•
1440
Write the date, the feed water pressure (manometer
optional) and the calculated pure water flow into a
maintenance plan. With the same method you must
evaluate the flow of the brine (closed flushing valve) and
write the value into the plan. With the following formula
you are able to calculate the ratio brine flow / pure water
flow:
ratio
brine flow
permeate flow
brine : permeate
=
Now you have to check the quality of the pure water.
The best method of measuring is the determination of the
electrical conductivity. You can also determine the water
hardness by quick test. Please use the instruction manuals
of these test. If you have determined the conductivity or
the hardness write the value into the maintenance plan.
Test the quality of the feed water in the same way.
Now you are able to calculate the rejection:
rejection
conductivity pure water
conductivity feed water
in %
= −
•
(
)
1
100
or
rejection
hardness pure water
hardness feed water
in %
= −
•
(
)
1
100
If the calculation is to complicated please use the
following table. Please chose the line with the conductivity
or water hardness of your feed water (for example
500 µS/cm). In the 2nd row you see the values that are o.k.
for the pure water (in that example 50 to 15 µS/cm). If the
water quality is too bad (conductivity is higher than the
values in the 2nd row), the reverse osmosis membrane has
a rejection below 90%. Please see "faults".
conductivity feed water
conductivity permeate in µS/cm
in µS/cm
with good membrane
100
10
to
3
200
20
to
6
500
50
to
15
750
75
to
23
1000
100
to
30
1250
125
to
38
1500
150
to
45
hardness feed water
hardness permeate in °dH
in °dH
with good membrane
2
0,2
to
0,1
5
0,5
to
0,2
7
0,7
to
0,2
10
1,0
to
0,3
15
1,5
to
0,5
20
2,0
to
0,6
25
2,5
to
0,8
Storing a reverse osmosis membrane /
changing a membrane
Storing a reverse osmosis membrane
You can stop an AquaCare reverse osmosis unit for a long
time without defects at the membrane. To prevent a big
bacteria growth (smell) on the membrane and on the pre
filter(s) it is better to make some steps before stopping the
unit for more than 4 weeks.
First stop the unit by closing the water tap. If there is no
water pressure in the unit (after c. 30 seconds), open the
pre filter(s) and drain the water. The pre filters may dry.
It is not allowed to dry the membrane. It would be
destroyed. Please disassemble all tubes from the
membrane housing (11) and close the open connections
with plugs (red plugs for inlet and permeate outlet, with
plug for brine). Now open the membrane housing and
drain the water. The next step is to fill the housing with
AquaCare disinfection solution (50 to 100 ml) and to close
the housing. Now the membrane can be stored for many
months without bacterial growth.
Important! Never store the membrane below 0°C
(30°F)! Ice destroys the membrane.
If you want to reuse the reverse osmosis unit please open
the membrane housing, drain the disinfection solution and
assemble the plant (see "Putting into operation").
Changing the membrane
If the membrane (12) is not in order you have to change it.
Therefore stop the unit and open the membrane housing
(11). Pull the old membrane out of the housing and push
the new one into it (first the part with the small ring
