"..........What's a water computer doing?
Turning the water of and off...."

And I thought that was a Tap.

You could make up a system with a solenoid valve to control the flow of
water and link it to a 24 hour plug in time clock (I bought 3 timers for
around £10.00)
David Hill
Abacus nurseries
www.abacus-nurseries.co.uk