Yeah it was you,I remember. First off your not going to use the m/h for flowering. You can flower with it, but it is primarily used for the veg. growth to keep the plants somewhat short and full. There really isn't enough red spectrum in m/h's for good flowering. As I say this I imagine there will be a few that will scream they use m/h for the whole grow. Though it doesn't make much sense to wait. You can make a cool tube but it is hard to do on a m/h bulb. Usually for a HPS bulb. Yhe m/h has a 4"+ width in the middle. For the HPS you get a PYREX baking tube and them clamp it to the reflector and clamp a hose to one end and some people then bring fresh air in the other end.I don't because my grow area stay relatively cool. Good luck!