LaMotte AM-41 Hydroponics Test Kit - Manual (Page 10)

5. Fill the Direct Reading Titrator (0383) with Standard EDTA Reagent
(5254). Insert Titrator tip into the center hole of the titration tube
cap.
6. While gently swirling the tube, slowly press the plunger to titrate until
the color changes from red to blue.
7. Read the result where the plunger tip meets the scale. Record as
Value A.
TI TRA TION B, CAL CIUM
1.
Fill the test tube (0645) to the line with nutrient solution.
2. Add 2 drops of *Inhibitor Solution (9258). Swirl to mix.
3. Add 2 drops of *TEA Reagent (3921). Swirl to mix.
4. Add 8 drops of *Sodium Hydroxide Reagent w/Metal Inhibitors
(4259). Swirl to mix.
5. Add one Calcium Hardness Indicator Tablet (T-5250). Cap and shake
until tablet disintegrates. Solution will turn red.
6. Fill the Direct Reading Titrator (0383) with Standard EDTA Reagent
(5254). Insert Titrator tip into center hole of test tube cap.
7. While gently swirling the tube, slowly press the plunger to titrate until
the red color changes to a clear blue which lasts for at least one
minute.
8. Read the result where the plunger tip meets the scale. Record as
Value B.
FI NAL RE SULTS
Calcium Content = 0.4 x Titration Value B = ppm Ca
Magnesium Content = 0.24 (Value A – Value B) = ppm Mg
EX AM PLE:
Titration Value A is 480 ppm CaCO
3
Titration Value B is 400 ppm CaCO
3
Calcium = 0.4 x 400 = 160 ppm Ca
Magnesium = 0.24 x (480 – 400) = 0.24 x 80 = 19.2 ppm Mg
10