The ornamental design for a grow light apparatus, as shown and described.
FIG. 1 is a front perspective view of our design of a grow light apparatus;
FIG. 2 is a rear elevation view of our design of a grow light apparatus shown in FIG. 1;
FIG. 3 is a front elevation view of our design of a grow light apparatus shown in FIG. 1;
FIG. 4 is a right side elevation view of our design of a grow light apparatus shown in FIG. 1, the left side view being a mirror image of the right side elevation view;
FIG. 5 is a top plan view of our design of a grow light shown in FIG. 1; and,
FIG. 6 is a bottom plan view of our design of a grow light apparatus shown in FIG. 1.
The broken lines show portions of the environment that form no part of the claimed design. Further, the portions of the grow light apparatus that are not shown in the drawings do not form any part of the claimed design.