bradostro

I was just wondering why the Belly of my green spotted puffer is gray sometimes but i can actually watch it change color to white when he sees me my wife does not believe me. When I come home from work and look in the tank his belly is white down the center and tiny gray spots on the sides of his belly but he sees me and starts swimming allover the tank then comes back to the glass and looks at me his belly will be completely white

pinkfloydpuffer

Hi welcome to fishlore
Grey bellies are usually signs of stress. It looks like you have alot of fish in that small of a tank. Really your little puffer's bioload is worth 30 gallons on its own. Are you watching your water quality closely? Puffers are extremely sensitive to water quality.
They can change color quickly to show how they're feeling. Maybe he is hungry and is happy to see you when you come home cause he knows you bring the food!

Slyf0x

^^ well said