My question is probably the opposite of what most people ask. My closet has 2 400w HPS in a homemade cooltube. The closet is about 3.5'x2.5'x7.5'. I vent my closet through my cooltube and it's working great, too great. My temps get down to 12c when light are out and about 15c when on. Is that too cold? Will this effect my yield in a negative way?