What species are you planning on keeping and what size vivarium are you using? Lights can throw off some heat depending on the type of bulb you are using so the fans are a good start. Also ambient temps can vary depending on where you keep the vivarium in the room. For example, I keep my theleoderma corticale near the floor on the cool side of my basement near 70 degrees but I keep my darts higher up in the more moderate section where it’s nearer to 75