If your water supply at the equipment pad is on a backflow preventer (check local codes) then you could tap into that and plumb in an irrigation accuator valve into your pool plumbing. You can control the valve with a battery operated timer. Hunter Irrigation makes one called an SVC (smart valve controler). Check out Hunter Irrigations web site /www.hunterindustries.com/Products/Controllers/svcintro.html/www.hunterindustries.com/Products/Controllers/svcintro.html