We recently transplanted 30 7' norway spruces and with the recent lack of rain. The customer would now like a price for watering them once or twice a week from july to the end of august of middle of september. I'm thinking somewhere between 15-25 gallons/tree. We will be using a 225gal tank with a pump. Will have to fill tank at least 3x from a hydrant. I'm thinking 2-3hr for everything?