TH KIT

Rinse the test tube several times with the water to be tested.
Fill the test tube with the water sample up to the 5 ml mark.
Add 3 drops of the Buffer Indicator to the test tube filled with the water sample. Close the cap and shake vigorously. The color will turn purple-pink.
Add the titration solution drop by drop until the color changes to green-blue.
Each drop of the total hardness solution is equivalent to:
- 1°dH (German Hardness Degree)
- 1.78°f (French Hardness Degree)
- 17.8 mg/L CaCO3

Water Hardness Classification

Water Hardness Classification
Classification	German Degree (°dH)	French Degree (°F)	mg/L (ppm) CaCO3
Soft	0 – 3.37	0 – 6	0 – 60
Moderately Hard	3.38 – 6.74	6.1 – 12	61 – 120
Hard	6.75 – 10.11	12.1 – 18	121 – 180
Very Hard	≥ 10.12	≥ 18	≥ 181

Note:
- Seawater is considered very hard due to various dissolved salts. Typically, seawater hardness is around 6,630 ppm (approximately 6.63 grams per liter).
- In comparison, freshwater hardness ranges from 15 to 375 ppm.

Water Hardness Conversion Table
	°dH	°F	ppm CaCO3	mg/L CaCO3	mmol/L	°e
German Degree (°dH)	1	1.78	17.8	17.8	0.1783	1.253
French Degree (°F)	0.56	1	10	10	0.1	0.702
ppm CaCO3 (USA)	0.056	0.1	1	1	0.01	0.07
mg/L	0.056	0.1	1	1	0.01	0.07
mmol/L	5.6	5	50	50	1	3.51
English Degree (°e)	0.798	1.43	14.3	14.3	0.72	1