Illness/Sickness: Help needed clarifying advice for a small floating axolotl

I have read several other threads on here mentioning floating axolotls but as ours are so small (2 inches) I am not sure whether some of the advice is appropriate, and I don't want to do anything wrong!

We were given two small axolotls about 3 weeks ago and within two days one started to float and get very bloated. They are still transparent, so you can see a large amount of gas/fluid around the organs. After about four days she (no idea, but we have decided they are girls!) magically deflated and looked like the other one, happily swimming around and spending lots of time at the bottom of the tank. Now, a week later she has inflated again but this time it is worse; she is bigger and now just floats on one side, or sometimes upside down at the surface. She still eats if fed but it is a struggle for her to swim. We were advised to gently squeeze her to try to release the air but I am a bit reluctant to do this - would it hurt/damage her if we do it wrong?!

We are following the care advice by the place that gave them to us: to change some water once every week or so, put the tank in a cool-ish place in the house, large stones on the bottom and a few plants, and feed daphnia and plankton and dried tubifex. They are also eating mosquito larvae, and when one pupated in the tank, the one that is now ill ate an adult mosquito that was thrashing around on the surface. Could that be the problem?!

Anyway. I know you guys must get these questions all of the time from newbie axolotl keepers but any help would be gratefully received!

Thanks!

The diet sounds good, except for the dried tubifex. This can be a source of problems. I would omit it and stick with live foods. Eating an adult mosquito shouldn't be a problem.

I'd suggest moving the floating axie into a very shallow tub, just deep enough that the animal has an easier time staying upright. Change the water daily.

You said you got the axies 3 weeks ago, and this is the most dangerous period for animals in a new tank. I would recommend testing for ammonia.
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