As you can see in the picture I have 20 pots in each tray. The tray is open on the bottom and sits in a bus tub. When I pot the seeds I use that pre moistened baccto potting soil. It is so moist it makes that radical take off. To water I just use a plastic watering can, with the spray end off. I put an inch of water in each tub on the end. I don't water directly on the seed. When I see the water level get to bottom of tub I put another inch in. I'd say right now the inch of water last 3 or 4 days.