A soilless plant growing system comprising: a receptacle having a bottom wall and one or more sidewalls extending upward from the bottom wall to a distal edge defining a receptacle open face, wherein the bottom wall of the receptacle is oriented to downwardly slope toward the fog production chamber such that water droplets condensed within the receptacle return to the fog production chamber; a tray sized and shaped to be positioned with the receptacle, the tray defining an underside and an oppositely directed topside, the tray further defining a plurality of openings extending between the underside and the top side; a fog production chamber in flow communication with the receptacle; a water reservoir in flow communication with the fog production chamber and including gravity feed provisions for enabling water flow from the reservoir to the fog production chamber, and maintaining a predetermined water level in the fog production chamber, the water reservoir including a spring biased outlet configured to maintain a predetermined water level in the fog production chamber; a piezo-electric element disposed in the fog production chamber and at a height below the water level in the fog production chamber, the piezo-electric element configured to generate water droplets from water in the chamber upon application of electric power to the piezo-electric element, wherein the water droplets migrate from the fog production chamber to the receptacle, wherein the system is free of covers or lids extending across either or both of (i) the open face of the receptacle, and (ii) the tray positioned with the receptacle. a receptacle having a bottom wall and one or more sidewalls extending upward from the bottom wall to a distal edge defining a receptacle open face, wherein the bottom wall of the receptacle is oriented to downwardly slope toward the fog production chamber such that water droplets condensed within the receptacle return to the fog production chamber; a tray sized and shaped to be positioned with the receptacle, the tray defining an underside and an oppositely directed topside, the tray further defining a plurality of openings extending between the underside and the top side; a fog production chamber in flow communication with the receptacle; a water reservoir in flow communication with the fog production chamber and including gravity feed provisions for enabling water flow from the reservoir to the fog production chamber, and maintaining a predetermined water level in the fog production chamber, the water reservoir including a spring biased outlet configured to maintain a predetermined water level in the fog production chamber; a piezo-electric element disposed in the fog production chamber and at a height below the water level in the fog production chamber, the piezo-electric element configured to generate water droplets from water in the chamber upon application of electric power to the piezo-electric element, wherein the water droplets migrate from the fog production chamber to the receptacle, wherein the system is free of covers or lids extending across either or both of (i) the open face of the receptacle, and (ii) the tray positioned with the receptacle.