Jabsco Impellers - Green, Blue, Yellow, or Black?

I just finished my permanently mounted fat sack pump. This is in addition to the three tank system built into my boat. The fat sack pump will be used to fill one or two of the extra 500lb sacks I use when we surf with a small boat crew.

I used a Jabsco Ballast Puppy with a yellow poly impeller. Unfortunately when the pump is not running and the boat is underway it leaks water. I have the ball valve on the pump but it's an impeller pump so it really should not need the valve to keep it from leaking. My simer pumps did not leak. I have read that there is a green impeller that is slightly bigger and is designed to stop the leaking. I am also interested in the blue Globe impellers.

Please let me know what you recommend and if it leaks water into your bag/tank.

Thanks,
Mike