Quote Originally Posted by DMand
I am using the PS234 kit. I did as you suggested and filled tube with pool water to the 25ml mark instead of 10 ml. But I need more detail. I put in only 1 scoop of the powder, do I need to add more than 1 scoop? I added 46 drops of FAS-DPD #2 until sample turned clear. How do I calculate the FC? I added 5 drops of FAS-DPD #3 and sample stayed clear.
You only need enough powder to turn the water pink. More won't hurt but is wasted. 46 drops are .2 per drop. Every 5 is 1ppm, so you have 9.2ppm of FC. If 5 drops of #3 leave the water clear and it doesn't have even a hint of pink, you have no measureable CC. If it's clearly pink you add drops till it goes clear. If you aren't sure, sit the tube on a white surface and see if it has a pink tinge. If you think it does and add 1 drop of #2. If it doesn't change at all, try another until it changes, or until you are sure it won't (3 drops at most). If it changes, each drop is .2 ppm of CC.