This quote addresses one of my concerns. I have seen posts describing how to add bleach. When I was using 6% from walmart, I slowly poured it into the skimmer flow. Now that I am using 12%, I would like to know if it is mixing correctly and how long after adding the chlorine is it safe to swim. I only have a skimmer and one return flow. The eyeball flow is pointed down and I can see underwater movement on probably half of the pool.chem geek said:Any source of chlorine improperly applied can result in liner degradation. For any concentrated source of chlorine, it needs to be thoroughly mixed with the bulk pool water. For Cal-Hypo, this usually requires pre-mixing in a bucket of water to get it to fully dissolve before adding it to the pool. Even when adding other powdered chlorine (Dichlor, Trichlor) or adding bleach or chlorinating liquid, it is important to pour slowly over a return flow with the pump running and then for extra safety to lightly brush the side and bottom of the pool to ensure thorough mixing. Even with bleach and chlorinating liquid, you could have them fall to the bottom of the pool as they are denser than water until thoroughly mixed.
Of course, there's nothing worse than a Trichlor puck (or granulated Trichlor) against a pool surface (for too long) as it is not only concentrated chlorine, but very acidic as well.