Irrigation of the Greywalls tee boxes is always an issue.  The smaller heads do not hold adjustment as well as the larger ones and zones stick on nightly wasting our time and causing us issues in the morning.  The pure sand based root zone is great for drainage; so good in-fact that it has very little soil moisture retention capability and causes us serious issues of LDS and drought stress if a zone or head malfunctions.  

This head completely blew apart from the top and caused a very dry 1/3 of a tee box before it was discovered.