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Middle line: multiply by 1 = gpg hardness as caco, Lower line: multiply by 20 = ppm hardness as caco, Middle line: 1 drop = 1 gpg caco – LaMotte AR-42 General Water Analysis Kit User Manual

Page 4: Lower line: 1 drop = 20 ppm caco

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4

7.

TOTAL HARDNESS TEST PROCEDURE

Add 1 Hardness

Reagent #6 Tablet

(4484).

Swirl to mix.

While gently swirling the tube, add

Hardness Reagent #7 (4487WT)

one drop at a time until the red

color changes to blue. Hold bottle

vertically. Count the number of

drops added.

Multiply the number of drops used in Step 6 as follows:
upper line:

multiply by 10 = ppm Hardness as CaCO

3

middle line:

multiply by 1 = gpg Hardness as CaCO

3

lower line:

multiply by 20 = ppm Hardness as CaCO

3

Fill the test tube (4488) to the desired line with the

sample water.
upper line:

1 drop = 10 ppm CaCO

3

middle line:

1 drop = 1 gpg CaCO

3

lower line:

1 drop = 20 ppm CaCO .

3

Add 5 drops

of *Hardness

Reagent #5

(4483).

1.

10

1
20

10

1

20

10

1
20

10

1
20

10

1

20

Swirl until

tablet has

disintegrated.

Solution will

turn red.

10

1

20

2.

3.

4.

5.

6.