Ammonia at .25 and axolotls slime coat looks slightly odd.

[KirbyandMudkip11]

Hello! So my male axolotls skin has started to look a little odd. His slimecoat had some issues so I tubbed him and gave him meth blue and an almond leaf. I added him back today but his skin still seems to be discolored. His ammonia tested around .10 ppm to .25 ppm so I did a 25% water change.
Nitrates and Nitrites were both 0. I know nitrates should be like 10 ppm, but mine have always been at 0 in all 3 of my axo tanks. I spent months cycling my first axolotl’s tank back in 2021 - luckily the nitrates being at 0 never seem to affect anything.
Please let me know what you think. I am just concerned about the white on him

 

[wolfen]

it isn't unusual for melanoid (dark) axolotls to have a dusty look with their slime coat but if their skin appears to be affected (areas/patches which look like scabbed skin) the areas will need to be swabbed with potassium permanganate.

 

[KirbyandMudkip11]

it isn't unusual for melanoid (dark) axolotls to have a dusty look with their slime coat but if their skin appears to be affected (areas/patches which look like scabbed skin) the areas will need to be swabbed with potassium permanganate.

Okay! Would you recommend swabbing the top of his head? - Like does the top of his head look unusual or bad?

 

[wolfen]

it does seem that his head has areas that are slightly worse than elsewhere which would benefit from being treated.