Illness/Sickness: Need help from experienced Axolotl owners...

Hello all, I have been chomping at the bit to post on here to get advise from you all. I have a young Axolotl named toothless who at first we thought was shedding but watching him and looking closer it looks like an infection. We got him on December 23rd and he seemed to adjust really well to his 10 gallon tank where was guppies and water lettuce in the tank as suggested by the pet store and then a few days ago my husband surprised me by redoing his tank using a black light glow in the dark fake foliage and glow rocks. He also got a filter that was to strong and stressed out toothless so got a smaller slower moving filter. Doing all the research I could last night I quarantined him in clean de-chlorinated water and he seems to be worse. Today he wont eat (and he is a great eater of live worms) and is fighting to swim/ not float on his back.. put him in clean de-chlorinated water and covered him in the fridge as a lot of people/ sites suggested. If you have any suggestions please I am desperate for help as this came on so suddenly.

Water temp: 58 degrees F
Just changed out half the water today. levels: Ammonia wont go down, still 0.25ppu Nitrite 0ppu and nitrate 0ppu
he has been removed from the tank and is in fresh water that I have changed after his salt baths. he has had two as suggested by our local vet I am talking to via email.
Took out all rocks other then the bigger ones.

Thank you again for reading...

Ok, its fungus, so doing salt baths is great! The guppies may stress him, though it sounds like they are pretty small. They also can add to the ammonia in the water, and may carry parasites, so it may not be a good idea for them to be with him. The filter along with the quick change no doubt stressed him out, and with the fungus also he is probably pretty stressed. I would try to not disturb him much. Him being stressed may also be the reason he wont eat. Ammonia at .25 ppm. isn't bad, it would be nice to have it at 0.00, but its not too bad. I am assuming that he is not in his tank? So for right now the ammonia in his tank wont harm him anyway. Nitrate should, in my opinion, be at least 5 ppm. Have you cycled your tank? If not, that could definitely be a problem, or the cause of this.

Hope this help! -Seth

Doesn't look like fungus to me, looks like chemical burn or heat damage. Salt baths may be doing more harm than good, try a tea bath instead. If you just did a 50% water change the ammonia must have been 0.5 before - this level will kill fish and amphibians quickly. If you got a new filter you have to start your cycle again, this is probably why you have ammonia.
Guppies are not suitable as tank mates, unless they are food, guppies like 24C and axies need 18C, and if they are not eaten they may attack gills thinking they are bloodworms.
It could also be the lighting, if you have a black light it could be sunburn. Axies don't like lights as they have no eyelids. Turn the lights off.

Keep your axie in a cool clean tub, change the water daily.

the guy at the pet store where i got him told me the same thing, that those levels can burn them. These are the only other fish they suggested he can be with because of the reasons you pointed out. he did eat them and im ok with that. each guppy is smaller then one of his legs. he did fine with the florescent bulb but not this black light...could it really burn him? also another thing that crossed my mind was that maybe it was the chemicals from the neon paint on the decor...

what is cycling exactly? what kind of tea and how do you do a tea bath?

Cycling is the process of growing beneficial bacteria in your filter, which will naturally consume ammonia and nitrite, converting them to nitrates. A complete guide is here:

Caudata Culture Articles - Cycling

Cycling is an important process to ensure the long term health of your axolotl and or fish.
There are also a lot of topics around the forums that will help you with the cycling process

Update: Toothless seems to be getting worse, he now has a sore on his tale that is almost see through and he is "fuzzy" on his body now too. I have been e-mailing back and forth with our local vet and will be taking him in tomorrow. He is really really thin and wont eat...Hope the vet can help...makes me cry that our little guy is so sick...

I wish you and Toothless lots of luck at the vet. I hope everything works out and he has some advice on how to proceed from here.