Big white fluffy lump on axolotl

[Parabola]

Hi everyone. First post.. please be nice : p

So, I'm an experienced fish aquarium hobbyist but I'm very new to keeping axolotls. This morning I noticed a rather large white fluffy lump growing on my daughters axolotl. Pics attached. It's a fairly new tank but it's cycled. Details: 60lt (15 gal), fine sand substrate, some java fern, anubias nana petite and hydrocotyle tripartita, sponge filter with ceramic biomax/noodles. ammonia is 0, nitrite 0, nitrate 5ppm, PH 7.4, temperature 18 degrees celsius (64F). Is it columnaris? Is a salt bath the best way of treating this? If so, is 3 teaspoons of salt per litre of water the right dosing? Anything else I need to know?

I'm so thankful to have this resource. Thanks in advance for your help with this!!

 

[Parabola]

Can anyone assist with this? Really need some advice.

 

[Calgarycoppers]

Do you use johns or holtfreters in the tank on a regular basis?

I'd recommend tubbing, 100% daily water changes, add johns or holtfreters to the tub and then use long term in the tank as well

 

[Parabola]

Thanks for your advice. Never heard of Holtfreters. Will jump straight on it. What do you mean by "tubbing"?

 

[Calgarycoppers]

Tubbing is using a plastic tub minimum shoe box size to 3 gallon container

You change the water 100% once or twice a day so you can monitor changes and control the temperature and parameters better than in a full tank.

 

[Parabola]

Thank you!!!

 

[Calgarycoppers]

You are most welcome