I have read from various places that you should give your lawn at least a full inch of water every time you water it.
What amazed me is that after this Melnor sprinkler ran at full blast for an hour and 10 minutes, it had delivered so little water that I couldn’t see much water some containers I set up around the yard. (This is a common way to determine the output of your sprinkler.) I don’t think this is a problem with the sprinkler per se; I just need to leave the sprinkler running for hours at a time to get the deep water penetration necessary to encourage deep roots.
Update: After 3 hours of watering, the rain cups barely measured 1/2 inch!