K-2006 test kit, just a few thoughts

[lstinthot]

So if there is no Cl` in the pool will adding more than 2 drop make the water change eventually? I did not go past 2 scoops as i was expecting to have very low Cl` levels.

Thanks

[Watermom]

No. If you get no pink color with two scoops of powder, then you have no chlorine in the pool. No need to add more powder -- will just waste it.

[chem geek]

If the chlorine level was very high, then you'd see a flash of pink when adding the scoops of powder, even if after two scoops it went clear. I've never determined exactly how much FC wipes out each scoop of powder, but I'm guessing that to have it stay clear with 2 scoops it would probably have to be quite high such as 40 or more ppm, though that's just a guess.

[waterbear]

So if there is no Cl` in the pool will adding more than 2 drop make the water change eventually? I did not go past 2 scoops as i was expecting to have very low Cl` levels.

Thanks

If there is no chlorine then there will be no pink color. the pink color (known as Wurster dye or Wurster's Red) is caused by a chemical reaction between the DPD and an oxidizer. If there are very high levels then the reaction proceeds further and forms a colorless Imine, hence the "flash" of pink as the Worster's Red forms and then disappears as it is further oxidized to the Imine. Adding more DPD powder will then react with the now lower level of remaining chlorine and the pink Wurster dye can form again and you can procede with the titration. The acutal AMOUNT of DPD powder used is not that important as long as you have enough to form the Worster's Red dye. If it only takes one scoop that is fine. If it takes 3 or 4 because of high FC that is fine. At very very high FC levels a yellow free radical is formed instead of Wurster's Red or Imine and that means the FC is too high to titrate.