Is my betta fish sick?

[Nana]

I bought my fish about a year ago.. for the past couple month he has stopped eating. Always at the bottom of the tank or hiding in the leaves..I clean his tank every 7 days. My other betta fish is fine but I am worried about the sick one ): I need advice!

 

[diana]

it depends .....how big is your tank ???

 

[maggie]

It really depends on the size of your tank and the temp of the water. He might be cold.