I have a Teel pump that I use to pump water from a river to water my garden. This year for the first time it does not shut off when I stop using the water. I took the top of the Pumptrol control unit off and with a screw driver, lifted the tab (magnetic I think) and the unit shut off. I'm assuming that I need to adjust the larger of the two screws to adjust the pressuer, but I do not know which way to turn it - increase or decrease pressure. I really do not want to screw things up so I'd appreciate an answer.