Question
hello,
I am looking to pump water from a cistern I have in order to water the lawn. The top of the tank is just below grade. The tank is approximately 8 feet deep. I tried using a 1/3 hp submersible pump I have and 50 feet of garden hose to see what happens. I attached a sprinkler head and then also tried a rotary sprinkler. Both worked, but water only made it about 3 feet out of each sprinkler both times. Is it possible to use a relatively inexpensive pump and garden hose to deliver enough water to 1-3 sprinkler heads to water the lawn? The furthest run of the hose would be about 125'. Is there an easy calculation to use to figure out pump size based on the length of the run? What is the best setup for my situation with the cistern?
Thank you for your time.
Matt

Answer
Matt,

Thanks for your question.
Pumps are made for a specific purpose. You probably are using a submersible sump pump. They are made to move a lot of water but only a few PSI. That's why your sprinkler only sprayed a few feet.
What you need is a centrifugal pump made for higher pressures. A 1/2hp would work, but you'll need 40PSI or about 90 foot. (pump pressures are measured in foot head, the psi x 2.31 = ft/h or the ft/h x .433 = psi)
I've included a link to an e-bay item which is generally what you are looking for. I'm not saying buy it, but that is the idea of what you'll need. (the price isn't bad though)
If you need a specific pump recommendation, reply back and I'll give you a few options.

Matt

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=230281087548&ih=013&category=...