How to set up my humidifier

Do I need cool mist or warm mist humidifier in my grow tent? I have 4 clones about 4 weeks. Grow tent in my dry basement, 64 degrees with 35% humidity. My led light is 200W, temp get about 75 degrees with heater outside the tent blowing in bottom vent hole, but humidity only gets around 40%, do I invest in humidifier?. Thanks