Illness/Sickness: Superficial fungus along Axolotl's body

[Nienora]

I am assuming this is fungus. All water parameters are perfect. Did a 90% water change yesterday. And rinsed out two of the four sponge filters in the tank. Torch the axolotl is 3 months old and house in a 40 gallon breeder with 5 siblings. This fungus showed up today and it's on either side of his flanks. No change in behavior; appetite is great and he's being his active, begging self. Question is, do I treat? If so, what? Is age a factor for treatment? I've posted some pictures of Torch below. Thanks for all your expertise!

 

[LSuzuki]

I'm surprised no one commented on this already. It doesn't look like fungus to me, but I don't know what it looks like. Has it gone away? Do you have more pictures?

 

[Skudo09]

Hmm I somehow missed this thread... It doesn't look like fungus to me either. I am not sure what it is. Could you post exact readings of the parameters including temperature? How did you rinse the filters? Does the white patch appear raised or fluffy like cotton wool?

 

[AxolotlChris]

Careful when doing large water changes as it removes all the ammonia from the tank resulting in the beneficial bacteria having nothing to feed on, which could crash your cycle.

Rinsing your filter out can easily wipe out your colony's of bacteria also crashing your cycle.