I have been worried about running my return pump dry. The safe level in my sump is only about 2 inches above the return bulkehead...The last couple of weeks I have caught it a couple times sucking air due to water evaporation. So I spliced a float switch into an old extension cord and plumbed it into my existing 37 gallon sump. I then took an old powerhead I had laying around and stuck it into a 5 gallon bucket, filled it with dechlorinated water and tested it out. It should be good for about a week and then I will have to fill the 5 gallon bucket...doesn't look pretty, but atleaast I don't have to worry about burning up a pump.
