That way you can determine which proportioner is malfunctioning and to what degree. It is always a good idea to have spare parts around, especially for the more important components such as proportioners, solenoid valves, pressure regulators, emitters, filters, etc. It seems as though things break down on weekends, or worse yet, on holidays. F. This can happen during extended cloudy and cold periods. Cool temperatures in the root zone reduce water and nutrient uptake.
Plants can wilt on a sunny day immediately following a cool, cloudy period.
If this is a problem, you might want to consider a bottom or floor heat distribution system to help warm the root area. Also, raising bags up onto a bench two or three inches from the floor, so that there is air space, will help insulate media from the cool floor. Media temperature is extremely important for proper plant growth. Sunlight Extended cloudy and cool days might cause too much delay in irrigation cycling. You might need to force the system on for a few cycles on these days.