Thanks, Watermom - I was able to get to it that way.

We are currently doing a blind vacuum - to waste - to remove anything that may have fallen to the bottom of the pool with this last Alum treatment. We know it had to have dropped something - we can now see the third step in the shallow end. we could barely see the second before. Once we've completed that vacuum task, I'm going to put the CuLator in the skimmer, and see if that does anything over the next 24 hours. We'll let you know.