I'm setting up a water efficient garden, so I'm buying a large tank
(4,500 litre) and also using a number of drums under the downspouts
around the house.

My plan is to pump water from the drums to the big tank, and thereby
hopefully never have to use mains water to keep my garden happy even
when growing thirsty vegetables.

My questions are - does anyone know where I could find a decent hand
powered water pump? Also, what type of pump would be best?

I want to use it to transfer water from the drums to the main tank.
I don't mind the physical exertion, but I would rather not have to use
a powered pump if I can avoid it.

Tom