I am sort of interested in this too but worry that it may be too whimpy. I have no bottom drains and lots of overhanging trees. Want something that can suck up all the leaves without clogging.
Yes. I built one using a swimming pool pump and a swimming pool cartridge filter. Use a two inch swimming pool vaccum line as a suction hose. Run the water through a leaft trap to get the big stuff. Then through the cartridge filter and back into the pond. It is mounted on a good size dolly. It works great but I have a few improvements I need to make. 1: build an on/off switch to plug the extension cord into on the unit, 2: put a check valve at the business end of the suction line, and 3: REMEMBER to not absent mindedly plug the pump in and let it run dry for long periods of time thus frying the impellers.
Number 3 is important as I did that not too long ago and am just now getting things put back together. I will try and get a picture later today.
Almost forgot...I built a copy of "The Freddy" from a post by Tom Lansing on NI several years past. I do have a detailed list of parts and how I put it together if anyone is interested.
I don't want to return water to the pond. I just want to suck up really big leaves and pump them to waste. Need an affordable pump which will self-prime and can handle a lot of solids.