Surface breathing

[Robbos]

Can anyone tell me why my fish often go to the surface of the tank on an evening. This doesn’t seem to happen through day. I do regular water changes, have an air stone need live plants

 

[Caliban07]

Do you feed just before the lights go out or an hour before?

 

[Robbos]

Just before

 

[Andy Sager]

Just before

That's mostly likely why. Fish get habituated to a routine so if they know it's getting close to feeding time, they are just getting ready for it.
You do need to be concerned if the fish go to the surface and start breathing heavily. That's a sign of low oxygen in the water so you would need to raise your air flow rate to the air stone.

 

[Caliban07]

I would say they are trying to release trapped air. They ate too much and can’t swim down because they are too full. It usually happens when the food is dry and expands in the stomach. Feed less or soak the food before adding it to the tank