Cool tube or hood for 6.5 foot tent

I just figured I would post this on here since I have a 4 x 8 grow tent setup with one vented 600w hood and one 600w cool tube with reflector wing. From my experience a cool tube is not for a6.5' tent, maybe my 240 cfm fan doesn't pull enough air but it cools the hood and not the tube as much because plants under the tube Always have symptoms of heat stress on the tops . I am not sure if it's the reflector Wing reflecting heat downards or focussing light more in some areas. This theory would make sense since the wing of the hood is integrated behind the glass and the heat that it reflects is vented out through the 6"duct , The heat from the cool tube on the other hand is reflected by the wing downwards and this heat is not vented out through the duct.
I am not sure if this has been discussed here before but I thought if I can help one other grower make a choice for his indoor lighting, It will be worth it.
Keep growing fellas!

there is a guy on here . he knows every thing .even better then god so he says ! ask gary .