Sick axolotl due to 6.6 pH?

[Kaiiak]

Hello, I have had two axolotl for over two weeks now. They were tubbed for their first week because the tank had not finished cycling yet (it took sixty days). My leucistic axolotl (satan) is doing fine, hangs at the bottom of the tank and eats. My other axolotl (Leo) has been doing awfully. I currently am fridging him. He was barely responding or moving and not moving his gills (“breathing”). He seems to be doing a lot better. He ate half a worm one day into the fridging and he has only ever eaten a half worm prior to that and before he was fridges he had refused food for six days. He is skinny now and I know appetite slows in the fridge but he seems to be doing better in there. My tank pH is 6.6 and his water in the fridge is 7.4 (which I believe is they’re preferred?). When he was in the tank he would try to sit on the very top of the plant/ hose connector near the top of the water also. I am not sure if maybe the oxygen saturation in the water is just not enough. I purchased a bubbler disc to put in today in case that is the issue. I have heard messing with pH is a bad idea as fluctuations cause undue stress (allegedly). Should I raise the pH? Or do you think it was the oxygen? Again, satan is doing perfectly in the tank.

 

[GulfCoastAxolotls]

Hello, I have had two axolotl for over two weeks now. They were tubbed for their first week because the tank had not finished cycling yet (it took sixty days). My leucistic axolotl (satan) is doing fine, hangs at the bottom of the tank and eats. My other axolotl (Leo) has been doing awfully. I currently am fridging him. He was barely responding or moving and not moving his gills (“breathing”). He seems to be doing a lot better. He ate half a worm one day into the fridging and he has only ever eaten a half worm prior to that and before he was fridges he had refused food for six days. He is skinny now and I know appetite slows in the fridge but he seems to be doing better in there. My tank pH is 6.6 and his water in the fridge is 7.4 (which I believe is they’re preferred?). When he was in the tank he would try to sit on the very top of the plant/ hose connector near the top of the water also. I am not sure if maybe the oxygen saturation in the water is just not enough. I purchased a bubbler disc to put in today in case that is the issue. I have heard messing with pH is a bad idea as fluctuations cause undue stress (allegedly). Should I raise the pH? Or do you think it was the oxygen? Again, satan is doing perfectly in the tank.

It would help to know what your water parameters are; Ammonia, nitrites, nitrates? Tank temperature?
What size tank are they in? How often are you doing partial water changes and how much are you changing?
What chemicals are you using in the tank? Water conditioner, ect.

You are correct that they do prefer a slightly higher pH, however your other water parameters are more important.

Photos of him would also be helpful

 

[Kaiiak]

Ammonia has been 0 ppm. Nitrites consistently 0 ppm. Nitrates about 5 ppm. Tank temp between 62-64 (I have a chiller). 50 gal tank. PWC one a week approx 30% only using prime as a conditioner. Sand substrate and hides/fake plant in tank. No other fish/amphibians. Trying to feed with worms, tubifex cubes and floating pellets recommended by breeder. Will add pics later. Thanks for your help.