To test for FC (free chlorine):
1. Fills the larger test tube to the 10ml line
2. Add one scoop of “DPD powder” (in the can)
3. The water should turn pink if chlorine is in the water. If it doesn’t turn pink, go put chlorine in your pool.
4. Add one drop of “FAS-DPD TITRATING AGENT” and swirl the tune to mix it up.
5. If the water turned clear in step 4, stop the test is done and you have 0.5ppm of FC. This is too low for anything and you should add more ASAP.
6. If the water is still pink, keep adding drips one at a time and swirling after each drop until the water turns clear.
7. Count the total number of drops you added and divide that number in half to get your total FC ppm.
for example, if it took 9 drops to turn the liquid from pink to clear, then the FC is 4.5ppm.