Today I put two 4 inch flexible aluminum tubes on the inlets and covered them with cloth with cloth and turned them at 90 degree angles, they do not let any light out. I will get 1 or 2, 4 inch fans to use. The one I have moves plenty of air but is a little loud I want to run it silent. Once I get the fans I will use a couple 4 inch tubes for the exhaust as well. Then I will truly have a stealth grow box. pics will be up tom