Alternatively, a group of small plants can sit in a large clear vinyl saucer above one of the holes in the plexiglass or in a clear vinyl saucer on a single shelf. Bonsai Bonsai plants sit well on single shelves with their pots in clear vinyl saucers. This way the plant does not have to be moved for watering and you can see the pot. Fill this area with water. If pots are set in holes in plexiglass above humidity trays, excess water automatically goes into humidity tray.
Water plants every two days on average.
Some plants like Azalea need to be checked daily. Alternatively, use wick watering from humidity tray. Water cacti once or twice a week. Poke a small hole in the center of large clear vinyl saucers resting above holes in plexiglass so extra water will automatically pour through saucer into the humidity tray. Use a nail to make the hole.