You want to choose emitter, it's the same as drip. Some places call them drip heads, other call them emitters. I determine how much water (in gallons) I want on each drip section and then set the amount of time to water. If your drip heads are 1 gal/hr and you want a half gallon on each plant, set the time for 30 minutes. This assumes you drip line pressure is around 15-30 PSI. Some lines may be as low as 10 PSI or as high as 50 PSI.