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I have a system which is 10 years old which just stopped working correctly. What is happening is that I am getting low pressure across all 6 zones which is causing some of the heads in some of the zones to not pop up and spray correctly and some to pop up but not spray under full pressure. System has hunter valves and heads on it. I have done the following. I have confirmed that there is no leak when the system is off. Meter does not spin. I have manually actuated each zone valve manually and still get the same symptoms . I have confirmed when one zone is on that there is no leaking on other zones. I have had a backflow specialist come check the valve and confirmed 70 psi on front side of valve and 67 psi on back side of valve. I have been told that pressure is normal. I had Seminole county come out and check and they say that pressure is correct to the water meter. I have dug up the water line almost to the water meter and the line looks normal ( the line splits after the water meter and runs to irrigation line. The other line runs directly to the house. Does anybody have any idea's of what else to look for. This is extremely frustrating. HELP