Illness/Sickness: New baby axolotl from Petshop, Have some questions!

So I acquired a new baby wild type, very light in color. It was kept in poor conditions
room temperature, and they had them in 4x5 critter carriers. I had to get it!

I'm fridging it now because it looked to be under a lot of stress from heat and the tip of the tail looked damaged and it's skin seemed to be shedding especially on it's toes. Tail looks a little better but still could use some healing.

So the skin looks better now after 2 days of fridge but before I put it in the fridge it's gills
were more fluffy and now they are a little curled and seems like dark dots on the tips of some of her gills fluffs. not on all of them just like 8 or so. I'm wondering if this is just because of the fridge and how cold it is. The temp is 42.

I want to say it's a she She's been eating some pellets I have (zoo med aquatic newt pellets) pretty nicely, 5 the day i got her, 3-4 yesterday and just 1 pellet today.

Seems active still and normal other than the tips of some gills. Dunno if I should be concerned and I looked forever through old threads but couldn't find anything about their gills.

Any ideas or thoughts would be appreciated.

Also, once she is done fridging, should I put her in the 20 gallon that has been running for a week or two now. Or should I just keep her in a small container until she gets a little bigger? She's about 2.5-3 inches long from head to tail and probably is only a couple months old.

The dots could be ammonia burns from it's previous care.

Gills will shrink in the fridge. For one, their metabolism is much lower, so their oxygen demand is not as great. For two, cold water holds more oxygen than warm water, so in the fridge, they need a lot less gill area to get the required amount of oxygen.

If your 20gal is ready for the salamander, you can put it in there. It will require a lot less maintenance as far as water changes, but because it's not fully cycled yet, you'll need to monitor your water quality pretty closely as far as ammonia and nitrites. You'll have to do water changes as needed.

Ammonia burns, I didn't think about that ha. Well she is looking better and better so hopefully the fridge is doing her some good. I think another day should benefit her some more.

Thanks for the suggestions on the gills. I knew there was more oxygen in cold water but didn't know why her gills would shrink or about the dots. I'll keep an eye on the water, I just got some dechlorinator and it removes metals too since my water tends to be more on the hard side so we'll see if that helps too.
I have ammonia and ph test kits but the ph test kit scale doesn't go very high or low 6.0 - 7.6 but should work for now. I have some plants in there but since it's a low light tank my options are limited to growing plants to balance ammonia and etc.

Thanks Kaysie

I wouldn't worry much about pH; axolotls can tolerate a fairly wide range of pH values.

Do invest in a nitrite and a nitrate test too. Get the liquid reagent test, rather than 'dipstick' types. Liquids are much more accurate.

Hard water is also fine for axolotls. My water you could use to hammer nails, but the axies don't seem to mind.

haha well that's good, i checked the ammonia levels on all of my tanks and they all read 0. and the ph levels are most likely around 7.6 or so which I've read that if you try and mess with the ph levels it could do more harm than good. yeah my other axolotl didn't seem to mind the hard water and he was happy.
but i will try to invest in the nitrate tests also. Thanks :]