Illness/Sickness: HELP! new juvenile axolotl floating!

I have 2 axolotls 1 male 1 female (Mickey Finn and Amber) who are around 7.5 months old and i decided to get another one the other day, I haven't had any problems at all with the other two and I got the new one (Ralph) who is 5 months old on Sunday, from the same lady who breeds them near me so i knew it would be safe and healthy. She said Ralph had had earthworms the night before and i took it home in a bag and put the sealed bag in my tank to get it used to the water temp and judge the reaction from my two. All was fine and i was going to put Ralph in a little tank for a while until he grew but he had been in a tank with adult axolotls so i decided to put him in with Mickey and Amber. It went well with no fighting or nipping so I fed them all earthworms, Ralphs were cut up a bit and he ate straight away. On Monday he was given a medium size worm by my boyfriend which wasnt cut up and i did say it may be too big for him but he only ate half of it anyway. By tues morning Ralph seemed a bit odd and i noted there was a bit of regurgitated worm in the tank and he couldnt stay on the bottom of the tank and couldnt stay bouyant on the top so i monitored him all day and by around 5pm he gave out a big burp of bubbles and a bit of worm which helped him but he was floating up again within an hour! His back end is still like that, he is hiding in the cave and he doesnt seem to have passed anything so do i need to put him in a shallow tank to help him or is fridging needed at this stage? He is about 5" long and is otherwise healthy and ate a tiny bit of worm today but refused the rest. He looks so uncomfortable

Hello

I had this problem with my axy's about a month back. They had floating butts for a few days - one almost to the point he was in a constant vertical position unless he wedged himself under an ornament or in a hide. When my first one did I totally FREAKED OUT. But it's nothing too serious as I have since found out All it is, is a build up of gas. It sounds funny but seriously all they need to do is fart. It gets rid of all the built up gas and then they are fine That is why when your Ralph let out a burp it helped ease the problem. I was told if it lasts more than two days you can fridge them but it isn't necessary.

Both my ones and my flatmates all came right on their own Also they didn't tend to eat much when they had this I guess because they were so uncomfortable. I was also told it's just caused from eating too fast or something similiar so you haven't done anything wrong Sometimes they just get gas haha

Thanks, I did read up a lot on the floating issue but was a bit concerned as he is younger than the others. I have just spoke to the lady who i got him off and she said he was eating frozen blood worms, earthworms and pellets and fed every 2-3 days. Surely every 2-3 days in not enough for a 5 month old axolotl? May explain the gas issue!