Hello roak2.0, The actual draw power for the 900watt light is around 400~450watt. The 900watt is the maximum output. In fact, many LED lights companies show the maximun draw output of the light in the specifications, but the truth is the light will not give out that much draw power normally. It is a world full of data, and customers prefer to choose the one with bigger drawer power, so we have to follow the trend, :Sharing One: But please do not worry, you will still get great result with our light in the recommended growing space. (900w for 4'x4')