Deep reflector = convection oven... Maybe go bare bulb, DIY parabolic reflector with 2 80mm's mounted on the top exhausting up n out... IMO for micro HPS bare-bulb cool-tube is the only way to go... More vertical height above the light source can also better help the heat exchange/dissipate from the canopy on up. I say though, you seem to be containing the 250w in your space better then some I have seen... I think your mold problem's might be a little strain influenced (Despite sativa's supposedly being more mold resistant, any bud that dense is at risk...)... Good growin' ...