Clownfish question

[superspider223]

My clownfish have marked this part of the tank there's. They are there every night and when im not near the tank feeding or cleaning. They have dug a bowl in the sand. Today I noticed the black one siting still under the heater. Is she okay?

 

[Mr. Mojo Rising]

Assuming your clowns are happy and healthy, then its fine, they do that when they are happy and resting. Its weird to see it at first but you get used to it