cheese, ..yea, you should see improvement since it is pretty much established that the ideal temp for cannabis is 74 degrees F..so you are right on.
The old theory that a 10-15 degree differential between daytime and nitetime temps was ideal has pretty much been disproven by the dutch...a constant 74 degree has proven to be best..although any night temps above 55-60 should suffice. Anything lower would probably slow growth. One way to tell if your nitetime temps are too low is the new growth will have more of a yellow hue to it than normal... I also added a 400 mh to the mix..so I now use 1 400 hps along with the 400 mh.. I keep the new plants going through the stretch directly under the mh and move them toward the hps until by the end they are directly under the hps..
thx for the kind words all.