Need Help Again, Please. Axolotl eating well but now floating

[Tadpoles]

To recap the basics:
A male, currently alternating daily between 2 small aquariums for a total water change whilst I cycle his 50 gallon home.
Water is untreated from a private well and has the following characteristics:

GH takes 21 drops of reagent to change color, which, according to API chart should be 375.9!
KH 18 dKH
pH 7.6
Ammonia 0ppm
Nitrite 0ppm
Nitrate 5ppm

I am maintaining him at 64F

I was having trouble getting him to eat but thanks to all the helpful advice he has been eating well - bloodworms and nightcrawlers.

Today he has been floating tail-up. He's managed to sit on the bottom a few times and has 'burped' out some air but within an hour or so starts to float tail-up again. At one point he gave in and calmly floated in a horizontal position at the top of the water but when he tried to go to the bottom, he obviously was struggling, trying repeatedly to swim down and stay there.

Reading through posts here, I checked the water chemistry. It is as above, no ammonia, no nitrates, 5ppm nitrates. Temperature is good (64F).

I have lowered the water level so he can keep his feet on the floor so he's calm now. He looks healthy color-wise, gills, tail etc. No external injuries. His tank is bare so no possibility of impaction from substrate. He has an airstone.

I have some concern that the small volume of water will be less stable in regards to temperature and ammonia, though I will change his water and the room is cold.

I am unclear on whether Holtfreter's solution is necessary with hard water, perhaps he would benefit from K and Na? Can I add these w/o a comprehensive water test to show how much is in the water I have? (I don't have access to such tests, just GH, Kh). Must Holtferter's be made with RO or distilled water?

Thank you again in advance.

 

[wolfen]

the main ingredients of holtfreters are sodium chloride, bicarbonate of soda, calcium chloride, potassium chloride, magnesium sulphate can also be added, the bicarbonate of soda ensures that the kh is good, calcium potassium and magnesium ensure that there are sufficient (correct) minerals and therefore ensures that the gh is good, the salt (sodium chloride) is for health and to help prevent issues like fungus etc.. axolotls are slight brackish moderate to hard water animals so they require salt/minerals to stay healthy.
holtfreters is mostly beneficial in water that lacks any salts or minerals although if the water already contains some minerals the holtfreters can be modified to add any that are lacking.
because your water has good kh and gh the only thing missing is sodium chloride, 2g/l being the most effective.
having a blacked out jar as a hide can be useful as somewhere for the axolotl to swim into until the air has been released.
the kh and gh tests are done to ensure that the waters carbonate hardness and general hardness are good, although there isn't any noticeable effects from having high kh gh the same cannot be said about low kh gh, low kh can lead to ph swings which are at the minimum stressful and if the ph drops too low damaging to both the axolotl and bio-filtration, low gh can cause illness in the axolotl from skin conditions to anaemia and also growth problems.
because axolotls unlike fish don't have swim bladders they can't stabilise when they swallow air and end up floating until the air comes out of one end or the other, this is quite common with young juveniles as they don't have the same body mass as adults.
reduce water levels will cause ammonia to build up faster although submerged shelves can be placed in the tank which will allow your axolotl somewhere to rest without having to lower the levels.

 

[Tadpoles]

the main ingredients of holtfreters are sodium chloride, bicarbonate of soda, calcium chloride, potassium chloride, magnesium sulphate can also be added, the bicarbonate of soda ensures that the kh is good, calcium potassium and magnesium ensure that there are sufficient (correct) minerals and therefore ensures that the gh is good, the salt (sodium chloride) is for health and to help prevent issues like fungus etc.. axolotls are slight brackish moderate to hard water animals so they require salt/minerals to stay healthy.
holtfreters is mostly beneficial in water that lacks any salts or minerals although if the water already contains some minerals the holtfreters can be modified to add any that are lacking.
because your water has good kh and gh the only thing missing is sodium chloride, 2g/l being the most effective.
having a blacked out jar as a hide can be useful as somewhere for the axolotl to swim into until the air has been released.
the kh and gh tests are done to ensure that the waters carbonate hardness and general hardness are good, although there isn't any noticeable effects from having high kh gh the same cannot be said about low kh gh, low kh can lead to ph swings which are at the minimum stressful and if the ph drops too low damaging to both the axolotl and bio-filtration, low gh can cause illness in the axolotl from skin conditions to anaemia and also growth problems.
because axolotls unlike fish don't have swim bladders they can't stabilise when they swallow air and end up floating until the air comes out of one end or the other, this is quite common with young juveniles as they don't have the same body mass as adults.
reduce water levels will cause ammonia to build up faster although submerged shelves can be placed in the tank which will allow your axolotl somewhere to rest without having to lower the levels.

Thank you. I'll add sodium chloride @ 2g/L and try to arrange a submerged shelf or jar so he can rest on the ground w/o being in a small volume of water, I should have thought of that.
Would you advise feeding him or not whilst he's in this state?

 

[wolfen]

if he will eat then feed him, try not to use any tank lights while he is floating as it will stress him out more (instinctively floating means being exposed to predators so keep the tank dark)

 

[Tadpoles]

if he will eat then feed him, try not to use any tank lights while he is floating as it will stress him out more (instinctively floating means being exposed to predators so keep the tank dark)

Will do.
Understood, there is just the light of another aquarium in the room, he doesn't have one on him.
Thank you so much for your kind help, I really appreciate it.

 

[Tadpoles]

if he will eat then feed him, try not to use any tank lights while he is floating as it will stress him out more (instinctively floating means being exposed to predators so keep the tank dark)

Not wanting to bother you but to let you know that I have followed your advice with good results:
This morning, he had not eaten but had defecated. He was still tail-up. I put him into his fresh tank, having treated at 2g/L w/ non-iodozed, no additive sea salt.
I put a brown glass Kilner jar in (not totally blacked out but very dark) and he has been content in there, allowing me to keep the tank full of water. He came out to walk around on his chin and front feet (pathetic and distressing) so I guided him back in his jar and he turned round to look out and settled down.
He's defecated again today. It's hard for me to see thro' the glass if he's floating at all but he is certainly calm.

 

[frogenjoyer]

Not wanting to bother you but to let you know that I have followed your advice with good results:
This morning, he had not eaten but had defecated. He was still tail-up. I put him into his fresh tank, having treated at 2g/L w/ non-iodozed, no additive sea salt.
I put a brown glass Kilner jar in (not totally blacked out but very dark) and he has been content in there, allowing me to keep the tank full of water. He came out to walk around on his chin and front feet (pathetic and distressing) so I guided him back in his jar and he turned round to look out and settled down.
He's defecated again today. It's hard for me to see thro' the glass if he's floating at all but he is certainly calm.

Please continue updating. Hoping for the best!

 

[Tadpoles]

@frogenjoyer Thanks for your interest.

Last night he came out of his Kilner jar and was back to normal, four feet on the ground, and eagerly ate a nightcrawler in pieces! I am much relieved.

Perhaps it was digestive gas and constipation/indigestion. I notice that feces from nightcrawlers are less substantial than feces from bloodworms. The latter you can clearly see what he was eating. Similarly, feces from Hikari carnivore pellets that I observed when I first got him look just like crushed up pellets/sawdust. This would suggest to me that the earthworms are more digestible and nutritious so I am glad he is on them again. Hard to say if the bloodworms caused his problems but they did coincide.

I would be interested in opinions on how varied their diet should be. Many people seem to recommend previously frozen Tilapia. If feeder fish are a poor choice b/c they may be disease vectors, would freezing them nullify that hazard? Would they then be possibly superior due to having organs etc. or is this where the parasites are, not the muscle?

He loves his jar and will sit in there looking out quite a lot. I will make this a permanent feature for him. I would take a picture but he's in there this morning.

Regarding wolfen's advice on salt, my research indicates that NaCl @ a rate of 2g/L should not be detrimental to the plant spp I have in his cycling 50g home (hard, cold water plants like Echinodorus cordifolius, Sagittaria subulata, Hydrocotyle leucocphala, Vesicularia, Limnobium spongia etc.) 2ppt doesn't even qualify as brackish. Wet Web Media say "A low-salinity brackish water aquarium can be treated as a freshwater aquarium for most practical purposes. Practically all aquarium plants tolerant of hard, alkaline water will also do well in slight brackish water at SG 1.003" So far as I can ascertain, 2ppt is approx. 1.002 SG This all makes sense to me considering where these plants can be found. I am slowly (abundance of caution) bringing his future home up to this salt level. WWM have useful information on brackish setups: Brackish Systems and FAQ's

 

[Tadpoles]

Please continue updating. Hoping for the best!

Sitting on top of his new house after a large meal of earthworm.