mt,

Is it strictly rain water collected or supplemented by municipal water? From the picture, I assume the latter. Two ideas come to mind, no three. 1) pay a neighbors son/daughter to run the system; 2) isolate the pressure system and rig a simple regular pressure pipe auto valve system with timer from a outside faucet(should be done for backup maint. of barrels); 3) install a small temporary electrical pump that is controlled from a timer. The pump can be a submersible pump that sits in one of the tanks or a separate small tank that is controlled by a float valve inlet from the other tanks. Just my $0.02 and JMHO. Very nice looking set up by the way. Aloha

Hi lehua13,
thank you for taking time to respond. the system is for saved rain water, our municipal water is very hard and will kill blueberries in no time( neighbor tried it).
As for hiring a teenager - this is being considered as a Plan B but I'd like to find a way to water automatically. Currently a pump is installed in-line. I use it to increase the flow, the problem is that after the pump is shut off water still keeps flowing.As can be seen on photo I even made the path from pump to watering line to be higher than the barrels(white pipe around the central barrel) but water still continues to flow after the pump is off, thus violating the law of communicating vessels, can't understand how and why :).