I live in southern Texas, outside Houston, so I understand it ALWAYS being humid! It's nice because it does keep the humidity around 50% all the time. I only need to mist when my snakes are in shed. However, I'm not sure what the humidity will be like once you add the heat lamp. But I definitely agree that it will be needed if you keep your house at 70*. Also, since you said you have a 55 gal aquarium, how big is your snake? That's probably way too big for an adult and way to big for a baby. Make sure you clutter it up with fake plants (You can keep the logs in there to take up space if you want) that you can buy from craft stores or Walmart. This will help the snake to feel more secure when it needs to move around the enclosure.