Thanks for the post back. It appears it is a Gast rocking piston diaphragm pump Model # MOAP101-AA it is a 1/16 HP pump. I called the distributor and they said it was good up to a 1/4 acre pond but looking at what you have stated I am not sure I would go that way. I was looking on the Gast site and have yet to find that model number pump. Any thoughts you might have or information you might find would be greatly appreciated.

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1/10 - 1/4 acre pond plus 16 ft deep/ Plus 40 ft by 20 ft by 6 ft deep koi and fathead minnow pond next to it. Upstate NY