LaMotte AG-103 Fresh Water Aquarium - Manual (Page 12)

PRO CE DURE
TOTAL HARDNESS
1.
Fill the test tube (0608) to the 12.9 mL line with sample water.
2. Add five drops of *Hardness Reagent #5 (4483) and mix.
3. Add one Hardness Reagent #6 Tablet (4484) and shake tube to dissolve
tablet. A red color will develop.
4. Fill the Direct Reading Titrator (0382) with Hardness Reagent #7
(4487DR) in the manner described in the instruction manual. Insert the
titrator in the center hole of the test tube cap.
5. While gently shaking the tube, slowly depress the plunger to titrate the
sample until the red color changes to clear blue. Read the test result
where the plunger meets the titrator scale. The result is expressed as
Total Hardness in ppm CaCO
3
.
EXAMPLE: Plunger is 3 minor divisions below line 80. Test result is 80
plus (3 divisions x 4) equals 92 ppm.
6. If the plunger reaches the bottom line on the titrator scale (200 ppm)
before the endpoint color changes occurs, refill the titrator and continue
the titration. When recording the test result, be sure to include the value
of the original amount of reagent dispensed (200 ppm).
7. Parts per million CaCO
3
test results may be converted to grains per
gallon (gpg) CaCO
3
by means of the following formula:
gpg CaCO
3
= ppm CaCO
3
x 0.058
CALCIUM HARDNESS
1.
Fill test tube (0608) to 12.9 mL line with sample water.
2. Add 6 drops of * Sodium Hydroxide w/Metal Inhibitors (4259). Cap and
mix.
3. Add one Calcium Hardness Indicator Tablet (5250). Cap and gently
shake to dissolve tablet. A red color will appear.
4. Now perform titration as described in Steps 3 through 6 of the Total
Hardness Test Procedure, titrating until the red color changes to blue.
Results are expressed as Calcium Hardness in ppm CaCO
3
.
MAGNESIUM HARDNESS
Magnesium Hardness (ppm CaCO
3
)
= Total Hardness - Calcium Hardness
12