Question
Hello,
I am a contractor for a company out of Dallas. I was recently sent to a job that the homeowner wanted me to put in a sprinkler system for a 100 x 200 horse arena.  The homeowner only wanted 6 sprinkler heads, and he wanted each sprinkler to spray at least 75'(ground level sprinklers)  He wanted me to install a 500 gallon plastic water tank and a pump large enough to do the job.  This is my question:  Do they make sprinklers that spray 75' and what size pump would be best to use.  Thank you for your time
Heath  

Answer
Heath,
Yes, they do, but thats about max distance out of any head I couold find. I looked at Rainbird and they make a head called the 8005. The book I'm looked at is not the new catalogue, but I'm sure they make something like it now and the Toro Golf Course heads are probably about the same as far as pressure and flow. That is the thing that you will need to get 75' out of the heads. The pump will have to supply 75psi and 35/40 gpm per head. The pump you will need will be big. The 500 gallon tank will run dry in about 15 minutes because of the large nozzle size needed to get 75' distance.It roughly comes out on the Cornell pump curve chart I'm looking at that you need at least a 4.0 horse power pump if you run 1 head at a time. might not be able to find 4.0 hp pump and may need to go with 5.0. Impellor size needs to be about 6.5 - 7.0 inches diameter. To pump 2 heads at once you are up to 70-80 gpm and there is no pump on the chart that does that. Double check with the pump dealer about the sizing here, but thats what I come up with. Also you will need 220vac and a lot of amps for a pump that big. The only way to get that distance from the head is big pressure and big nozzles and that means big pump, but it can be done. let me know. Jim