Well your DO levels aren't great but you're right... it shouldn't be lethal to BG from what I've read.
But that doesn't sound like the only thing going on. I would get some water samples analyzed to see if you can find another cause.
Is your pond fed by a stream or surface runoff?
This is just a WAG but maybe the spacing of the rain events was enough to set up another thermocline and you've been getting multiple turn-overs?
Regarding the aeration - if today might be too late, tomorrow is definitely too late.
Bottom line is, your pond is telling you that something is out of balance. If you're still getting fresh fish kills after two weeks, you really need to pinpoint the cause(s) and correct it(them). Maybe you can contact Florida Fish and Wildlife Conservation Commission?
I wish I could give you a more direct answer. Good luck and keep us posted. I know that I had assumed you got an aeration system and that it was working - until your last post anyway.
