Because the surface of pots stays dry with the Ebb and Flow MAT capillary mat irrigation systems unlike with other irrigation systems such as overhead irrigation systems and micro-drip irrigation. Fewer airborne spores germinate and algae and liverwort growth in greenhouses is inhibited.  The surface of the Ebb and Flow MAT’s should remain relatively dry at all times except in the immediate area of pots being irrigated. The fact that surface splash of water on the media and fertilizers is minimized, and produces a drastic reduction in algae and fungus formation. The dry surface conditions in the top of the pots reduces common pest such as fungal gnats as well.