As always I will start with a background story.
Way back in 1991 the UK was experiencing a drought, hosepipes were banned and my garden needed watering. I decided that I would collect all the grey water from my house to use in the garden, I will not go into the whole system but the important bit was that there were a number of water butts full of water that needed to be sprayed around the garden. This is a job for the bucket pump!
The picture is an article in the local paper of the time and yes that is me 25 years ago. The picture also shows one of the water butts, the car battery, the hose and most importantly the floating bucket!
Step 1: The Bits
The items required are all easily available:
A car windscreen washer pump, preferably with a bottom inlet (I obtained a number of these from the local car wreckers for next to nothing)
Rubber grommet (frequently already fitted to the pump)
Adapters of various sizes to suit
12 volt battery
A water detector circuit
Step 2: Control Cicuit
I wanted the system to be as automated as possible so rather than just a switch to turn the pump off and on I built a circuit to detect water or lack there of.
It is very simple and was built on a small piece of veroboard prototype circuit board (it could equally be just a birds nest of soldered connections) contained in a small enclosure to keep it dry.
The probes are just a short piece of heavy twin household wiring (the flat type uesd for wiring plug sockets with the earth wire cut off short) with the ends bared.
Note! You can do without this circuit, just run a couple of wires from the pump with crocodile clips at the other end to attach to the battery. The only thing you lose is the automatic switch off when the water butt is empty.
Step 3: The Build
The bucket needs a hole in the bottom for the grommet that will seal around the pick up tube of the pump plus two holes for the probe wires, sealed with silicon sealant.
I attached an old steel pulley under the bucket (with a small gap between it and the bucket) as ballast to keep it upright in the water and to protect the pump inlet and probes.The probes need to be set a little higher than the pump inlet as shown.
The outlet of the pump needed to be adapted to attach a standard hosepipe, any one with a bit of nouce should be able to work that out :)
I tie-wrapped the battery wires to the hosepipe to keep them tidy for connecting to the 12 volt battery away from the water. (I later found a couple of burglar alarm batteries that fitted inside the bucket making it much more self contained).
Step 4: How It Works
The grey water is collected in various places around the house, the bucket and battery get taken to one of the butts, the pump hosepipe gets connected to either a hand spray (as above) or a lawn sprinkle, the battery is connected and the bucket floated in the water, this switches the pump on. It will continue to pump until either the bucket is lifted out of the water or the bucket settles to bottom and the probes come out of the water, as the pump inlet is set slightly lower than the probes it will never end up pumping air.
No build photo's as I did this 25 years ago and no longer have it, my current system is far more modern but this setup worked very well for many years.