Black clownfish turning whiteish

[Elton99]

Hello
I purchased a pair of black clownfish 3 months ago maybe 4. And they started turning whiteish.
Almost like they rolled in dust.
Very hard to capture the photo but the fish have appetite, swim healthy, everything seems to be normal but getting faded parches of white on the skin. Even in the eye on one fish ! Very hard to capture a photograph.
But it doesnt appear to be a ich like the white dots. Just turning lighter color in rather large patches.

 

[Elton99]

 

[Elton99]

 

[Elton99]

 

[j.falk]

@Humblefish

 

[C. Eymann]

Definitely wait for other opinions before taking action, disease and treatment is not my strong suit, but looks like brooklynella to me.
Best treatment for brook is formalin if I remember right.

 

[Elton99]

This worries me alot because all of my frag tanks are plumbed together and connected to the same sump. Each of the tanks house a pair or clownfish

 

[Humblefish]

Brook: https://www.reef2reef.com/threads/brooklynella.247938/