I started with a python, which is a big version of a basic aquarium gravel vac...not my favorite tool
I broke down last year and bought a Pondomatic. It is boxed up at the moment, but I will see if I can find a link for it. It is not the newest version, but works great. It fills, shuts off just long enough to drain, and then starts up again, so there is a little lag (like maybe 30 seconds to a minute), but that comes in handy for moving around and seeing where you want to vac next. If you look the vacs up by brand, rather than at a particular website, you can sometimes find screaming deals out there. I got mine on huge sale, and with free shipping...end of season sale, maybe...
http://www.pond-doctor.co.uk/bradshaws_ponds_pumps_0223.htm
This is the only link I can find quickly...I don't think they make the pondovac 2 anymore...saw lots of 3's and 4's though. Biggest difference I could see is the newer ones have a dual chamber so it pumps and dumps at the same time, no lag...and a few extra zeros in the price!! Might have been why mine was not so expensive, if it was a discontinued model
http://www.oase-livingwater.com/en_...]=2272&cHash=f4879f14dcd081c82214bea5fdecbb4e
Here is another one, looks and sounds identical to mine, but they are calling it the 'classic'
Jen