My sister has a leopard gecko. Right now he has a 75 watt bulb, but even with the heat on it only gets to be about 70 at most in her room. The highest I ever have seen the tank get is 76*. He is in a 20 gallon long tank with sand substrate. What would be the highest watt I should use for his tank? I think it's been to cold in there for him to properly digest his food, he eats crickets, and today he pooped out a cricket whole.

Under tank heaters work better for leopard geckos are they are nocturnal and do not bask. If the tank is not warm enough after adding that you can use a heat lamp. For my tanks I use 75watts.

Also replace the sand with paper towels, newspaper, shelf liner, reptile carpet, slate tiles, etc.. Sand is a horrible substrate that only causes health problems. Leopard geckos in the wild do not live on sand anyway.

I have 3 leopard geckos

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