Front part of fish darkens strangely, and only one side

[leafhorn]

Just noticed one of my red fin kadango females, which colouration is usually orange, have the front half of her body at the right side darkens.

The head & the shoulder area darks and stops at the center of the body, forming a straight line contrast of brown and orange, and it is only on the left side. She almost look like the front portion of a Tropheus Duboisi.

What happened to the fish. Behavior is normal and eager to eat, doesnt seems stress too. The only thing is that I noticed it after a filter maintainence and a 50% water change. (50% water change freqeuntly is usual for this tank) Of course she might had been like that for a day or two before the filter maintainence and water change, perhaps I did not notice earlier? Please help, I am rather worried.

Additives are added as usual, marine and epsom salt, baking soda.

[leafhorn]

Just noticed one of my red fin kadango females, which colouration is usually orange, have the front half of her body at the right side darkens.

The head & the shoulder area darks and stops at the center of the body, forming a straight line contrast of brown and orange, and it is only on the left side. She almost look like the front portion of a Tropheus Duboisi.

What happened to the fish. Behavior is normal and eager to eat, doesnt seems stress too. The only thing is that I noticed it after a filter maintainence and a 50% water change. (50% water change freqeuntly is usual for this tank) Of course she might had been like that for a day or two before the filter maintainence and water change, perhaps I did not notice earlier? Please help, I am rather worried.

Additives are added as usual, marine and epsom salt, baking soda.

[leafhorn]

Just noticed one of my red fin kadango females, which colouration is usually orange, have the front half of her body at the right side darkens.

The head & the shoulder area darks and stops at the center of the body, forming a straight line contrast of brown and orange, and it is only on the left side. She almost look like the front portion of a Tropheus Duboisi.

What happened to the fish. Behavior is normal and eager to eat, doesnt seems stress too. The only thing is that I noticed it after a filter maintainence and a 50% water change. (50% water change freqeuntly is usual for this tank) Of course she might had been like that for a day or two before the filter maintainence and water change, perhaps I did not notice earlier? Please help, I am rather worried.

Additives are added as usual, marine and epsom salt, baking soda.

[leafhorn]

Just noticed one of my red fin kadango females, which colouration is usually orange, have the front half of her body at the right side darkens.

The head & the shoulder area darks and stops at the center of the body, forming a straight line contrast of brown and orange, and it is only on the left side. She almost look like the front portion of a Tropheus Duboisi.

What happened to the fish. Behavior is normal and eager to eat, doesnt seems stress too. The only thing is that I noticed it after a filter maintainence and a 50% water change. (50% water change freqeuntly is usual for this tank) Of course she might had been like that for a day or two before the filter maintainence and water change, perhaps I did not notice earlier? Please help, I am rather worried.

Additives are added as usual, marine and epsom salt, baking soda.

[DEA]

i have no experience with the fish you mentioned
i would say though, keep a close watch on the fish, and change your water frequently and see if it clears up
i think adding anything to the water without having any idea of the actual condition of the fish is more harmful than not doing anything