clown acting weird

[netopr]

Hi, 3 days ago, my clown started acting weird. He is just standing in one corner floating next to a power head.
It all started after I painted my background to black and I dont know why since I masked everything very very well...
The water parameters were all good except for high nitrate 40ppm which I made a water change...

 

[dawman]

You didn`t use spay paint did you ?