Don't let your room get below 55 F when the lights are off, that will stunt the plants growth, and possably kill it. Plants need warmth when they go through photosynthesis, thats also when they use co2, Plants only go through photosynthesis when the lights are on. So I would recomend a light duty heater, because you live in a warm climate. Make sure when your lights are on. the temp goes back up to normal