Planning new cabinet

Starting to get everything together to build a new and first cabinet. I have done a lot of woodworking in the past and figure that I could build what I want cheaper that buying a cabinet. I have read many posts regarding their cabinets but still have a question as to what is the best thickness wood to use. I was thinking of using 1/2" plywood as I have a few sheets in the barn. Is there any other types of plywood or other material that would be best due to a warm humid environment? Trying to prevent it from warping. Any help would be appreciated. Planning on the size to be 5'tall x 3'across x 2'deep. Thought this would provide enough space for approx 5-6 plants. Will be using a 400w HPS for the grow.

sturdy pine would be the most durable wood. you should consider going 3X3X5 this will allow room for 6 plants.

I hope you have proper venting..........Something to consider if you going to be running a 400 watt.

Hank.

you're going to require proper venting. Look for proper blower fans (120cfm - 440cfm) and then possibly and intake fan of equal or near outtake. They will run you a decent penny but its really the only true way, axial fans will _not_ work, they can't overcome static pressure.

a 400watt gets hot, especially enclosed in a volume of 45 cubic feet, the dimension quoted above.