Strange red dot-like rash?

[VoidDaddy]

So Cheese has been eating normally for the past few weeks. Their diet is mostly small earthworms and shrimp-- in fact they just ate 5 small earthworms and a few bits of shrimp earlier today. They're acting normal. Their tank parameters are 0 nitrate 0 nitrite, 7.6-7.8 PH (give or take), ammonia is 0, Chlorine is also 0, alkilinity is about 160-180 (give or take) . The parameters are, overall, ideal. The only thing a bit alarming is the temperature of 20-21 celcius (68-69.8) which I know is a bit too warm but a 150L chiller I ordered is currently on the way. I live in the UK and the heat wave has been hard on Cheese, but I always keep it at 21 celcius maximum even during the worst of the 27-30 celcius heat fluctuations in my room.
Also don't worry about the red gills in the pictures, that was just because they didn't wanna be taken away from the bubbler that they like to sit near by so they became very active as a result lol.

The weird 'rash' dots only started appearing after I put not only some moss balls but metal-ring suspended hammocks made of fine netting, all on the same day. I took the hammocks out over a week ago due to the metal rings not actually being water proof so they started to rust. Even though that sounds bad, I'm confident it isn't that. I even did a 90% water change after removing them whilst ordering stainless steel ones as they really loved to sit on the hammock. And their condition hasn't really changed much at all. Some days it seems worse than others. I only just took out the moss balls earlier today on the off chance they were causing whatever this is. But I still have no idea what exactly is wrong with Cheese. They're about 6.3 in or so, and I got them when they were around 3.5 in. I'm rather sure they're a female due to their proportions and the lack of an enlarged cloaca. They did a big poop a few days ago and a poop earlier today so it doesn't seem to be any impaction / blockage related issues.

After reading online I saw only one or so other person on caudata had a similar problem to mine back in 2010, but they never said what fixed it (if it ever was fixed) or what was wrong. There's no signs of fungus, I keep a very close eye on them and have clipped all the sharp points I could ever find on all of their fake plants so I know it isn't that. I would really appreciate the help!!

 

[wolfen]

keep an eye on temperature, the blush can be caused by the water being too warm, this is mostly noticeable in albino's and lucy's.
get a liquid freshwater test kit, strips aren't sensitive enough and are just for quick testing for major issues, unless your tank is new and un-cycled or you have a means of nitrate removal other than water changes (ie.. plants, special media etc..) you won't have zero nitrates.
apart from heat blush (can also be caused by exertion) your axolotl looks fine, the photo's aren't clear/close enough to see any skin issues, the gills are perfect with no curves or reduction and are lovely and red so is getting plenty of oxygen, can't see if tail is hooked but if the gills are anything to go by she doesn't look stressed.
you need a more accurate water parameter reading.
your axolotl does look female but can't really see with the finger/fake plant in the way.

 

[VoidDaddy]

keep an eye on temperature, the blush can be caused by the water being too warm, this is mostly noticeable in albino's and lucy's.
get a liquid freshwater test kit, strips aren't sensitive enough and are just for quick testing for major issues, unless your tank is new and un-cycled or you have a means of nitrate removal other than water changes (ie.. plants, special media etc..) you won't have zero nitrates.
apart from heat blush (can also be caused by exertion) your axolotl looks fine, the photo's aren't clear/close enough to see any skin issues, the gills are perfect with no curves or reduction and are lovely and red so is getting plenty of oxygen, can't see if tail is hooked but if the gills are anything to go by she doesn't look stressed.
you need a more accurate water parameter reading.
your axolotl does look female but can't really see with the finger/fake plant in the way.

Sorry for the delayed reply, I got busy with irl stuff.

Temperature never gets hotter than 21. managed to get it down to 20 the past few days. I have an open top with frozen bottles of water left floating on the top of the tank. I also keep the window wide open and the blinds closed but giving it room for air to circulate. I also keep the door wide open. I try to promote as much airflow as I can to keep the room cool.

I got a hold of a liquid test kit and the parameters of my 120L from 2 days ago are as follows:
PH 7.8
NH3 0
NO2 0.3
NO3 5.0
I didn't test KH or GH as I couldn't figure out how to do those because I'm number dyslexic. The reason why I did it 2 days ago and not today is because yesterday I decided to fridge her and since then she's pooped a lot as I was worried she was constipated (and it seems I was right). The flushing / blush has indeed gone down so I think you're right on the cause being temperature. I just changed the water in her tub and gave her some bloodworms and she's doing fine. A bit bored but fine lmao! The tail hasn't been hooked since the one occasion and that was the day I got her. I'll try to take some more pictures in the future to try and tell the gender for sure. She's about 6 and a half months old so she might just be a late bloomer if she's a male, since I read that it's possible for some to develop their male maturity later than others.

 

[wolfen]

your nitrites are bad everything else is ok.
how was the tank cycled, if it wasn't cycled or done properly then you will have more water issues as she gets bigger.