Netafim Arkal 2” Spin-Klin Compact Stand Alone Filter Installation And Operation Instructions Manual page 17

Cleaning Carbonates and Iron Deposits

Open the filter and remove the dirty discs.

Arrange the discs loosely on the plastic rope.

Prepare a 5% Solution of Hydrochloric Acid:
1. Pour 10 liters of water into one of the large containers.
2. Carefully add 2 liters of Hydrochloric Acid (30%) into the water. Soak the discs in the solution so
that both sides will be covered.
PLEASE NOTE: Carbonates react violently with hydrochloric acid (foaming, gas evolution). To achieve
maximum cleaning, agitate the discs several times with a stirring stick.

Contact time with cleaning solution: 1 - 8 hours.

Remove the discs carefully from the solution and rinse them well with clean water before placing them back
in the filter.

We recommend flushing the cleaned discs again in the filter to ensure that all chemical residues are
removed.
The cleaning solution can be used for several sets of discs. It may be necessary to soak the discs for a longer period of time as
the cleaning activity of the solution deteriorates.
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.