Hey dude,,,

Don't let got of the 400W MH... that doesn't make sense.

In your setup, do you have fresh air (from outside the window) coming inside? You need fresh air.

As to the a/c unit, that would kick-ass, as you would be able to mantain very exact temperatures, and not be dependent on the enviroment (like me).

I trully think that your problem is you're not getting fresh/cool air in there...

Please post updates,

-turtle420