I've gotten rid of the problem. I've increased the water temperature, add some salt in water and gave a KMnO4 bath for my Parrot. I've also vacumed the debrises from the gravels and did a 50% WC
. Then suddenly, today I've noticed that the parrot doesn't have any white spot in his skin. I belive that the treatment worked fine. But I think I should continue the treatment for atleast 1 week more to get rid off the issue totally.