Disease on my Angel

[Decarnocimex]

Hello!
My angelfish is swimming akwardly and I don`t know why. I feed him 2 times a day with special flakes and ocassional treats of mosquito larvae. If you know what is happening to my angel please post here. Thanks

 

[ewurm]

Is it hanging near the bottom?

 

[Decarnocimex]

yes, and it doesn`t looks so active as before.