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
| 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 |
| °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 |
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.