Farm Innovators Drain Plug De-Icer; Say goodbye to frozen stock tanks this winter with the Farm Innovators Drain Plug De-Icer. This de-icer delivers 1500 watts of power and can be used in all Rubbermaid stock tanks with drain holes (sold separately). It’s designed to fit through the drain plug hole for easy installation, and is unnoticeable to livestock. This submersible de-icer is suitable for tanks up to 300 gallons. It’s thermostatically controlled to operate only when the water temperature reaches 35 degrees or less, saving you electricity.