Wow! Thanks!
Research is way better than consensus (but takes a lot longer to read).

I see that research referenced in the WHO report indicated that 50mg/ml borate should be effective in supressing / eliminating several of the algae species studied as has been experienced by many. Why, I wonder, would the borate pool product providers label thier product dosage (from the EPA report) at ten times that rate? Is the idea to use boron as the primary sanitizer?

I'm not sure I can stop the kids (mine and others in the neighborhood) from drinking a tablespoon a day no matter how much I insist. I suspect somebody pees in it (CC spikes) even though I personally look each swimmer in the eye and say "The potty's just through the door, not in the pool". On the other hand, they don't swim every day and we only have a pool in the summer and the research suggests chronic exposure is more of the problem than acute episodes ("Sorry Dad, I didn't mean to drink a half gallon of pool water, I was thirsty").

I think I'll try it next summer - almost time to drain, dry, fold, and store.

I am still interested in anyone else's experience with borates positive, neagtive, or neutral.