Q. To keep the water safe against pathogenetic bacteria the residual chlorine should remain between (Solved)
1. 10 ppm to 20 ppm
2. 1 ppm to 2 ppm
3. 0.2 to 0.8 ppm
4. 0.05 to 0.2 ppm
5. 6 ppm to 10 ppm
- d. 0.05 to 0.2 ppm
1. 10 ppm to 20 ppm
2. 1 ppm to 2 ppm
3. 0.2 to 0.8 ppm
4. 0.05 to 0.2 ppm
5. 6 ppm to 10 ppm