LG,
Hola,
A lawn or garden should get about one inch(2.54 cm) of depth of water a week if it was raining. Place several cups out on the lawn to measure the depth of water in the cups per watering cycle. Let us know what depth you measure. My guess is your are over watering, especially with fungus forming or grass starts to yellow. Without knowing the water output your system is generating, it is just a guess. I would cut back watering to about 4 minutes per day, once a day, every other day and see how the grass or plants take it. This is called an experiment. go out and check the moisture in your soil by digging about 5 cm into the ground and see if there is moisture after your water stops. Do the cup thing to find out exactly how long to run your system. That is called a water audit. Placing cups all over the place will determine how even you system is water all parts of your lawn. If you do this you will be the gardening expert in your area. Aloha

You are generally better off watering longer but less often. When you water small amounts very frequently, the lawn and garden stay wet on the surface nearly all the time, making an ideal environment for fungus problems. Plants also don't put down deep roots since they don't need to, so are more susceptible to drought stress if there is a gap in the watering, and if your sprinklers aren't completely uniform, you get patches that never get enough water.

By watering less frequently, but with more water so it soaks down in, the surface will dry out and reduce fungus problems and the roots will go down deeper to follow the water.

I water usually once a week, sometimes every 5 days during the hottest part of the summer when days are consistently in the 90's--it depends on when the grass starts to show water stress, but the water will reach a depth of 24 inches or more from each watering. My climate gets virtually no rainfall, so irrigation is all it gets. When we do get measurable rain in late spring, then I will space the watering out further, based on when the grass just starts to show some drouth stress.

What I'm getting at is let the ground dry out to a depth as long as your middle finger or a little more, then give it a good watering, then let it dry to that depth before the next watering and set your timer to follow that schedule.