MANOWNROSM
SYSTEM MAINTENANCE
US Filter
23
2.
2% Citric Acid, pH 3-5
Add 200g of anhydrous citric acid to 9L RO water.
3.
1% Sodium Bisulfite, pH 5-6
Add 15g of sodium bicarbonate (NaHCO
3
) or 10g of sodium carbonate
(Na2CO
3
) to 10L of RO water. Add 100g anhydrous sodium bisulfite
(NaHSO
3
). The pH of the solution is approximately 5. Adding sodium
bicarbonate or sodium carbonate before the sodium bisulfite, adjusts the
pH and minimizes sulfur dioxide gas liberation.
4.
0.1% EDTA/Na-EDTA, pH6
(EDTA is ethylene, diamine, tetra acetic acid.) Add 10g of Na-EDTA to
10L RO water. Add 10g EDTA. pH is approximately 6.
5.
Hydrochloric Acid, pH2
Add 0.5L of 1.0N HCl to 9.5L RO water. This amount of HCI will vary,
depending on the buffering capacity of the makeup water. Check the
addition of acid with a pH meter.
6.
Sodium Hydroxide, pH12
The amount of NaOH needed will vary, depending on the makeup water
quality. If solid NaOH pellets are available, add 4.0-40g to 10L of RO
water. Check the addition of caustic with a pH meter. If 50% NaOH is
used, start with 5ml per 10 liters, and add until a pH of 12 is reached.
K.
Shutdown Procedures
1.
Short-Term Shutdown (Less than 48 hours)
The RO systems may be shut down for up to 48 hours with no adverse
effects to the system or cartridges. No special re-startup procedures are
required.
2.
Long-Term Shutdown (Greater then 48 hours)
If the RO system is shut down for longer than 48 hours, fill the system
and cartridges with a sanitizing solution to prevent the growth of bacteria
and to help maintain proper flow rate. The following table lists the
recommended concentrations of storage solutions of the RO cartridges.
Storage Solution
Concentration
