How long to wait before re-test

[BigDave]

Did you add the bleach in front of a return? That can help it mix. Did you sample in a "dead" are with little water flow? Did you add the bleach in such an area? I would hink that with strong circulation, an hour and a half would be plenty of time to disperse the bleach - clearly it was not.

[billp]

I spread the bleach around the whole perimeter of pool. Samples are taken on the back side of a return and between a skimmer, but there is pretty good circulation there. Always thought that was the best place, but I may try the front side of return.

Thanks.
Bill.

[PoolDoc]

I'm guessing, based on having seen colored additives spread in a pool, but on a small pool (< 25,000 gallons) an hour should be OK, if the pool has both an operating skimmer AND main drain. With only one skimmer and one return, 2 hours would be safer.