help me please

i need advice on auto grow ive got some auto in soil now for almost 30 days on 18/6 under a 430hps ive got a 1000 mh but its been so freakn hott and my ventalation yea until it cools off outside i need to leave the 430 up but its lookn like i could put the 1000 up next week maybe first timer growing auto when do i turn back the light to 12\12 or do i need to i herd its better for the plants to turn the light back too 12\12 and youll get better resultsie bigger buds any advice please and how many of us do co2 im starting to hear that if your room doesnt get above 90 degrees the plants dont even use the co2 is this a wifes tail or what