James,
Someone will answer your question, not me...but I did want to ask you to consider 1 inch or 3/4 pvc instead of the cheaper poly tubing.
When I installed mine, a 600 + foot run, discussions with the supplier revealed that the poly tubing is never pressure tested before shiping and can on ocassions have pin hole leaks right from the manufacturer. Leaks that would be almost impossible to find when installed and leaks which would drain away your pressure. PVC, although more expensive, avoids this potential problem. Also, pvc is much more durable, stands up to external force (driving a tractor over it). Something to consider...my advice is don't save a penny to loose $.
