I have the following pump setup with 6-8 ft suction and 4-5 feet head. Water comes from a 300 underground tank. http://www.harborfreightusa.com/usa...o?itemid=47906&CategoryName=&SubCategoryName= This has worked great for manually watering over the past year. When the water runs out I just flip the off switch. It'll run "dry" for 30 secs or so, but has water from the head so it's not totally dry. It has never triggered the thermal protection. I'd like to try something automatic. For this I figure I need dry run protection. I've looked around for types of pressure and float switches, but can't find anything cheap for this. The thermal protection is "auto-reset" which I figured would just make the pump come on again once it cooled down, which is undesirable. Any ideas to make this work, cheaply?