Thank you all so much for all of your advice, it helped tremendously! My temps are now staying solid and are not fluctuating so much. The cold side is at 78°, the hot side is at 83°, and the thermometer under the substrate and over the UTH is at 89°. My only question is on humidity, the hot side is at 49% and the cold side is at 59%. I know the 59% is good but is 49% too low?