Hi James….. Water through once with the pots outside the trays, allow to drain and ensure the base of the pots are clean before placing in the tray….. then allow to establish and then turn the water on after 10-20 days depending on the weather….. If you look at the largest plant and feel the weight of the pot this will give you a good indication. If you feel a little apprehensive you can turn the water on at the reservoir for 30 mins and then turn off for a few days and repeat this procedure for a week and then turn on the reservoir permanently.