Pump for stored rainwater

Afternoon all.
I have a plan. Well, several actually, but this is so I can setup an irrigation system for the garden running from stored rainwater. To get things running though I think I would need a pump that would start when I turned on the tap of the waterbutt (or whatever) and off again afterwards or if the water level go too low/ran out. Does anyone know what I should be looking at pump wise? Would it be fitted inside the water butt or the other side of the tap?
Has anyone else done this? Also, can I use a loft header tank for the water to give me larger storage? Or would something else be better?
TIA
David.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
David wrote:

I pump all my domestic water from a 1000 liter tank fed by a spring. The pump has a pressure switch on it. Pressure drops, pump switches on. Actually I have a pressure tank too that is effectively a reservoir of under pressure water so that the pump doesn't kick in every time I fill a glass of water.
I got my kit from Andrew MacWilliam who was very helpful via phone and email when I was deciding what I needed and then working out how to set it all up. http://www.andrewmacwilliam.co.uk /
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.