If you wet the grass via sprinkler, it will still have that "100%" environment you talked about, right? The reason it's suggested to water during the dew period is twofold, as I understand it. First, it doesn't prolong the wet period beyond the number of hours of the natural dew. Second, dew is not only water; it also contains plant exudates, which provide a food source for fungal organisms. Watering durning this period washes these exudates from the plant, thus robbing fungi of the food source. From a Colorado State publication on watering: "Irrigating between 10 p.m. and 6 a.m. also overlaps with the turf�s natural dew period. Most diseases of turf occur when grass blades are wet for longer than 14 consecutive hours. Watering before 10 p.m. or after 6 a.m. extends the natural wetness period and increases disease problems. Dew contains substances exuded from the plant tissue. These materials increase the growth of disease organisms. Water applied between 10 p.m. and 6 a.m. dilutes these materials thus reducing the growth of turf disease organisms."

are the openings about 1/4" or 1/8" inch if so look on the side and do you see a common screw all that you need to do is take a screw driver and turn them until the water stops. These openings are test cocks that is were the testers connect their gauges. Here is a link that might be useful: do_it_your_self_site

In-ground boxes were used; however, they were overgrown with grass. We finally managed to locate all 7 zone valves and the master valve. It only took about 10 hours, but we found them all, and cleaned them out. That was 80% of the time spent on this project. Lesson learned...keep those valve cover areas weedeated out every week!! The root cause appears to be sand from our well. We get this really fine sand from the Paluxy Sands in our well water. We had severe sand issues for a while after first digging the well, and apparently it was enough to cause problems in the irrigation system 3 years later! The sand got into the diaphragms in the valves and blocked the little pin holes that allow the valves to close. That, combined with lowering the water pressure slightly, would not allow the valves to close. Thus, multiple stations would be running at the same time. Everything is working better than before now, thank goodness! I found a great site for electrical troubleshooting that helped a lot (link below); that helped narrow down the possibilities right off the bat. Here is a link that might be useful: Sprinkler System Electrical Troubleshooting

Distance between heads is about 55'. I forgot to mention when the line(3 lines total) comes out of the valve and into the yard they simply "T" off and go to each sprinkler. The sprinkler closest to the point where it tees is about 10' away where the other sprinkler is over 40' away. The line coming into the house is 3/4" copper. I'm 100% certain because I put a ball type cutoff valve in(and replaced the hose bib with a ball type) when we had to tee off for the sprinkler. Rather have a close easy to get to shutoff valve than run out to the street and fight with the valve on the meter in case something happens.