a/c stays at 70F, my biggest problem is temp and humidity, i found that with the 460cfm fan and plenty of ventilation outside the hut temps wont be such an issue on the inside, on the other hand my 40gal res keeps plenty humidity in the hut so i have a pretty heavy duty dehumidifier outside the hut, im depleting 5gals every 2 days from my res, one day my fan didnt come on due to a misscalculated timer, temps hit the 90's and it was as muggy in there as a sauna, let alone the glass on the hood you could have fried an egg, i couldnt imagine trien to deal with a 1000 watt light without a cooltube