Extremely Stunted growth/Sick Axie?/Water bubbles

[PeterTse]

Hi! I am fairly new to this website though I have used it for answers a while. I had no knowledge of axolotls and wanted to get one two years ago, so I did. I have done a lot more research now but am wondering if I went wrong from the start (most likely). I am 15 and have a 27 month old axie (about 2 years and 3 months). Theoretically, from what I've seen and heard, he should be full size by now (around 8-12 inches if I am correct). He is only a little more than 4". I was concerned about this after a year, and when I asked my local store where I purchased him from, they gave me some "good" advice and told me not to worry. So I didn't. But I feel like this is an extremely bad case growth wise.

I was also concerned about him changing color on me. When I purchased him, he was the muddy brown color. But over the course of about a month he lost his coloring and is now an albino. I've never heard or seen a case of this when I looked online and was just wondering if he had chemical burns/a reaction or if this is just an adjustment to water/environment.

Water: He has pretty excellent water parameters, nitrite, nitrate, and ammonia stay at 0 ppm all the time, and his pH level is about ~7 or more. He is in the lower floor of our house so his water temp stays around 55-65 degrees, maybe up to 70 in the summer. I change his water about every two weeks (should I do more? please let me know). I have a 20 gallon tank.

Feeding: I started him on bloodworms, which is what the pet store recommended, then I grew concerned about his size and switched to mysis shrimp and have been feeding him that for a while now. I also have pellets but he seemed to have floating issues after eating them so I try not to use them (idk if that's what I should do or not) but it could be because he is so small. Should I switch to bigger worms? Is it too late for him to grow?

He's had issues with bubbles before, his rear floated sometimes, but recently (for the past week) he has had bubbles inside of him. He has been upside down and not eating so I just moved him to a small container with shallow water. Should I put him in a bigger one for now? I don't really know any of the chemistry or chemicals or anything I should or could use and frankly don't have the money for it either. If I should take him to an exotic vet please let me know.

Thank you to anyone who reads this post, and please be kind. I am an amateur and yes that isn't an excuse for laziness but I just want advice here.

I will take some photos if that would be helpful. Thank you!

 

[wolfen]

best doing a tank water change weekly, helps to maintain ph as well as keeping nitrates under control, what are your kh gh? ph should be 7.4-7.6, bicarbonate of soda can be used to increase ph.
with floating, tub in shallow water (shallow enough that his feet touch the ground) ensure that the water is cold and oxygenated, change water daily, feed at night change in morning, it will take time for the air blockage to pass but it isn't unusual for smaller axolotls to have this issue.
was the air bubble that he has trapped been caused by air bubble gulping (standing over air stone) or by surface gulping? if air bubble gulping install finer air stone, if surface gulping ensure adequate water oxygenation.
bloodworms are fine as part of a varied balanced diet as are mysis, make sure to give a variety of food sources to ensure a healthy diet.
although smaller axolotls are unusual it is not uncommon, in a large batch of eggs a few will be small or deformed, normally these would either die or be eaten by larger siblings, sometimes they survive and you end up with axolotls that are below the norm.
it isn't unheard off for an axolotl to loose it's pigmentation although the cause isn't understood, it could be due to genes or it's regeneration ability or some other cause, this seems to be an area that hasn't been researched although it doesn't seem to affect the axolotls health.