The timing and amount you water depends on your soil type, soil condition, soil quality, rainfall, sunshine, clouds, temperature, humidity, shade trees, tree roots, grass type, grass height, wind, barriers to wind, and probably some other factors I'm forgetting. Once a week summer watering works in Phoenix but not necessarily in Las Vegas (different soil types/quality and altitude). Once a week is a guide and a good place to start. The more important point is to encourage people not to water every day for 10 minutes. Water deeply and let the grass tell you when to water.
If you have not been watering deeply, continue to do that even if you have to water every other day for awhile. Keep an eye on the grass, as you are doing, to know when to water. But always water deeply.
You might mix 50/50 baby shampoo and molasses. Both are surfactants which will help your irrigation water penetrate more deeply. Apply at about 6 ounces per 1,000 square feet from a hose end sprayer. Spray right before you irrigate once a week for a month. You should notice the soil becoming softer to your feet when you walk on it.
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