Wattage has a lot to do with it. You need a lamp that has a dimmer switch. The bulb wattage should be no less than 25 watts and no more than 50 watts for day and night bulbs. You can use the red one for day and night if needs be. The reason you buy a lamp with a dimmer switch is so you can adjust the amount of light and heat coming from the bulb. This way if you don't need the bulb up to full strength to produce the amount of heat needed then you don't have too. Do you have a Under Tank Heater (UTH)? you need one of these to help keep the tank warm because they need a constant heat source. DO NOT! place the UTH on the bottom of the tank despite the name of the heater being "under tank" these as you know are burrowing frogs and can easily be burned or overheated if they burrow over the heater if its placed on the bottom. What is the wattage of your bulbs?