Something grown on Cardinal's scale

[Morgan01]

sorry for the poor picture as it's extremely difficult to catch them still.

wondering anyone who has kept cardinal has seen this thing growing on their scale? thanks

[sfk7]

My best guess is fungus?

How long since the last time you have cleaned your filter?

[khtee]

is it white in colour? You picture shows yellow line.... difficult to see from the picture.

[Morgan01]

Its white color. 1 vertical line. So I need to separate it? Previous cardinal healed after sometime.

My tank is only 3 months old. Maybe cos it's overloaded with fauna.