It stays plenty moist enough, the water seems to wick up faster than it can dry out. I did it this way last year and also on the germination tests this year. I'm about to add more water to the bottom tray. I haven't added any for three days and the bottom tray isn't dry but needs water. I can live with watering every three days. The top of the soil is still perfectly moist and with the heat mats underneath, the soil is nice and warm. I put a strip of 1/2" masking tape on all the plastic labels so I can reuse them. I write the variety on the tape, then just peel off the tape for next time. This is the third time I've used those plastic markers. They are very durable unless they are left out in the sun for a long period, then they get brittle and need to be throw away.