I really didn't like the original mini whale electric pump installed in the show drain. It had several problems:

1. It used electricity
2. It would not self-prime (even though it was supposed to)
3. It wouldn't completely drain the sump

I looked around for electic alternatives, but what I saw was too expensive, to big, and a lot more trouble than it was worth.

Instead, I bought a bellows-type, self-priming, manual floor pump. You can see it here. I installed it on a board so that the rubber dome lies just under the removable floorboard.

The pump takes anywhere between 25 and 35 pumps to drain a 3/4 full sump -- with no electricity!!! Since I had previously replace the fiberglass shower floor with an open grate, I have a filter in line before the pump.In between the filter and the pump is a 5 dollar check (one way) valve to try to help the draining process. It helped some, but it still does not drain the sump completely dry.