DPD powder

[waterbear]

If you OTO test turned dark orange then it means that you have high chlorine levels. DPD will bleach out at high chlorine levels making you think you have NO chlorine in the pool. Have you tried adding more than one scoop of DPD powder...sometimes that will work. Taylor recommends adding the DPD powder by the scoop until the pink color holds.

Also it is possible that you have no FC in the pool, only CC. When you add the third reagent to test for CC does it turn pink then? (even for a second?)