PEP Filters TOWER CLEAN PACKAGE - Manual (Page 9)

Cleaning Complex Deposits
If the composition of the deposit is not known, perform the following test:
Take 5 discs for the test.
Soak 2 discs in a 5% Sodium Hypochlorite Solution.
Preparation of the solution:
Pour 1 cup of water into a small container, then add 1 cup of Sodium Hypochlorite
(10% NaOCl).
Soak 2 discs in a 5% Hydrochloric Acid Solution.
Preparation of the solution:
Pour 2½ cups (= 500ml) of water into a small container, then add carefully
½ cup (= 100ml) of Hydrochloric Acid (30% HCl).
Keep one disc as a control.
Observe the cleaning process:
- If one of the solutions removes all of the deposit, clean the discs in that solution
according to the instructions above.
- If neither solution removes the deposit completely, continue with the test procedure.
Remove the discs from both solutions, rinse them well with water and soak them in the
second solution: put the two discs, which have been in the Sodium Hypochlorite Solution,
in the Hydrochloric Acid Solution, and the other way round.
Check the cleaning process:
- If one of the treatments removes all of the deposit, clean all of the discs following the
same two-step procedure in the exact same order. Rinse the discs well between the
two cleaning processes.
- If the deposit hasn’t been completely removed, send a set of untreated discs to the
laboratory for further examination.