75 isn't enough, you need 87-90 on the hot side, 93 max and 78-83 on the cool side, also 50-60 percent humidity at all times.
Increase humidity by putting a big water bowl near the heat source, and misting the sides of the tank, not too much though
you can get a cheap controller for your heat at your local petsmart or petco, for 21.99 for now, that will work fine.