Sorry to hear that Allan. There are some bonafide aeration experts on here, I expect one or more will be along shortly. It is my limited understanding that many brands of pumps are rebuildable, or at least can be freshened up with a variety of kits.

Are there any identifying names/numbers on your pump?

"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.