to pump water up hill you need 1/2 PSI per foot. Say the 'head' is 100ft, that'd be 50PSI pump required + losses and such, so a solid 75 PSI. Now decide on how many GPM you need to 'refill' the reservoir to replace what you used. It's a numbers game.... 1000 cuft of water is 7,000 gallons, a...