Mysterious white patches

[harpreno]

I posted earlier, wondering if this was Ich, and thanks, everyone, for reassuring me that it was not. But. What is it???

Four days ago I noticed two white patches, showing on either side, where the fins meet the body (picture 1 below). The lfs recommended a water change and dosing with API Bettafix, which I did. I have dosed the tank every day, per directions.

Details:
Planted 10 gal. tank; Rusty the betta is the only occupant. 0 amm., 0 nitrites, 5 ppm nitrates, Ph 8 (consistently), temp. 80 F. The fish seems perfectly fine, active, and with a normal appetite.

But by today, the white patches seem to have spread so that they are touching, and seem to be expanding along the length of the fish (pictures 2 and 3).

Thanks for any expert advice you can offer--I am a total newbie, not to mention a nervous fishmom.

 

[ImACoolguy]

With bettas it could just be a color change..

Does it look fuzzy?


Caleb

 

[harpreno]

Are the white spots fuzzy?

Caleb,

Thanks. The white spots don't appear fuzzy. I can clearly see the texture of the fins. It looks like normal fish skin, etc., just without color.

Bettas change color??? It's enough to turn a fishmother's hair gray(er).

Bev

 

[coralbandit]

Some say the color change is do to 'marble' gene in the fish!
Marble Betta Fish – Color Changing Genes | Betta Fish Care