Why do you think you need a flow sensor? They are more used for on demand systems that have the potential to cause mass amount of water loss/ damage if an issue/ break occurs.
There are other means that fit pricing better for residential.
If it was my place and I wanted to monitor flow - particularly if you are on a pump from a pond where the chances of having a Main Line break or stuck zone run 24/7 are Zilch. I would simply use a De-Duct meter that will count the amount of water I would use. A Deduct meter is basically just a water meter that you can install after your pump and would count the amount of water used.
The most reasonable price for residential use to have a flow sensor would be a Hunter ICC or I-core with the Solar Sync ( Dumbed down version of a smart controller ) and a Flow-Sync.
You should also simply document your zones design. For example if your zone has 15 heads and they all have nozzle of 1GPM. That equates to 15GPM usage. Say the zone runes 3x a week for 30 min each= Thats 1,350 each week or 5400 in a month. Adjust this for seasonal month to month
Last edited by mitchgo; 02-21-2013 at 04:50 PM.