Definitely FA, and you've got it bad alright. As others have mentioned, getting a head start on it is paramount to controlling it. If it's any small consolation, It was terrible in one pond of mine last year, so I got on it early this Spring, and now there's no sign of it.
In the meantime, I agree with manual removal - a lot of work, but low cost, I used a fine mesh net and scooped it out when it drifted to shore on windy days.

"Forget pounds and ounces, I'm figuring displacement!"

If we accept that: MBG(+)FGSF(=)HBG(F1)
And we surmise that: BG(>)HBG(F1) while GSF(<)HBG(F1)
Would it hold true that: HBG(F1)(+)AM500(x)q.d.(=)1.5lbGRWT?
PB answer: It depends.