Juvenile Axolotl swimming to top of tank. I'm concerned. (SOLVED)

[astrocresent]

I just got my axolotl about a week ago so I'm fairly new to this whole thing. He has started periodically swimming to the top of the tank and falling down. I've seen some say it's normal but I've also seen it could be a lack of oxygen in the tank. I have two moss balls and a sponge filter in the tank and the water temp. stays around 65. He appears to also have trouble swimming when he does go to the top of the tank. He's about 3 inches so I know he's still probably young. I'm also not sure if maybe he goes to the surface more because of the nip in one of his gills (the shop owners kept all the juveniles in a tank together). And now he has started being more uninterested in his food. I use aquarium tweezers and feed him blackworms everyday. Idk if I'm just being overly paranoid or if there is something I need to do. Overall he doesn't seem to be in bad condition and I think he enjoys having a tank all to himself but these little things just make me worry.

UPDATE: So it turns out that my axolotl had swallowed a pebble from the tank he was in at the pet shop. Fortunately he was able to pass it. Since then he has been eating regularly and I haven't seen him swallow any more air. He's no longer having trouble swimming, I didn't even know axolotls were supposed to be able to swim all around with ease. I'm so happy I got him away from that shop. It made me sad that they were all in a small tank together and many were missing limbs because Juveniles will nip at each other. I truly believe that my axolotl is so much happier in his nice 20 gallon with plenty of food and no pebbles for him to swallow. I'm so relieved that he's ok now.

 

[edanded]

That can be fairly normal. If you’re worried maybe add an air stone? Did you cycle your tank before adding your lotl?
Sometimes it takes them a while to get used to their new environment too, they might go off their food and their behaviour might be a bit off. However if he continues to be off his food it’s likely your levels are off or something else is the problem.
The other possible concern is - can he get back to the bottom of the tank easily? What is your substrate? As he’s only little, the only recommended substrate at the moment is bare bottom as sand and gravel is likely to get compacted which will cause a whole lotta issues.
Best of luck with your little cutie

 

[astrocresent]

That can be fairly normal. If you’re worried maybe add an air stone? Did you cycle your tank before adding your lotl?
Sometimes it takes them a while to get used to their new environment too, they might go off their food and their behaviour might be a bit off. However if he continues to be off his food it’s likely your levels are off or something else is the problem.
The other possible concern is - can he get back to the bottom of the tank easily? What is your substrate? As he’s only little, the only recommended substrate at the moment is bare bottom as sand and gravel is likely to get compacted which will cause a whole lotta issues.
Best of luck with your little cutie

Thank you so much for the help! I think his system was a little backed up because after some pooping he was very interested in his food lol. He seems a lot more lively now.