humidity levels just add soil seeds water and love sunleaves super starter plugs ... are designed to drain off excess water from the base of the germinating seed ... cutting while maintaining a proper air/water balance oasis horticubes are available ... and fill the tray with about an inch of water as moisture evaporates the grow plugs ... soak up the tray s excess water to keep seedlings and cuttings moist ... you need only periodically add water to the tray depending on the seed or ... insert in their reservoir to wick water directly rather start your seeds in ... heat mats are flexible ul listed and water-resistant to use one simply place seed flats ... and humidity domes are also helpful for trapping heat and moisture within your growing ...