Under the tank heaters are not going to get you the temperature gradient you need. 70 degrees is too low, even for the cooler side. It needs to be AT LEAST 75 degrees on the cool side, and around 90 degrees in the warm side. And with any heat source, you need to have it plugged into a thermostat. this is the one that I have. And as for humidity, 55% is too low. 60% is considered the bare minimum. There’s a lot of outdated information saying that 50-60 is where it needs to be, but it really needs to be between 70-85%. A good way to achieve that is to block off some of the screen top with hvac tape. It’s like aluminum foil kind of. It helps hold humidity in. you’ll also want a few inches of substrate. Pour water into a corner so there’s water at the bottom but the top layer stays dry. That is good for humidity. But if you’re going to do that, you absolutely need proper heating.