Phosphates (Sensitivity 0, 5 – 30 mg/l(ppm) PO4-3 ) Method :
1) Rinse the test tube with the water to be tested and fill to the 5 ml mark.
2) Add 2 drops PO4 – A indicator and shake the test tube 10 seconds very well, then add 2 drops PO4 – B indicator and shake 30 seconds very well.
3) Compare the blue color to color reference color chart to determine concentration of orthophosphate in mg/l (ppm)
4) Color comparison must be completed within 5 minutes.
