Questions about setting up tank

[entirely em]

Tank size
I have a juvenile axie that i got back in February. It was a little under half an inch when i got it and I've had it for a little over 2 months now (about 3.5 inches now). I'm not 100% sure how old it was when i bought it though so i don't know exactly how old it is. I've been keeping it in a tub and doing 100% water changes everyday, but i really want to move it into a proper tank. The problem is: I've seen people saying that the absolute smallest tank you can have is a 20 long. I get that, but I wanted to take my axie to college with me, and the dorm rules say fish tanks cant be bigger than 15 gallons. I've been thinking about getting a custom made 15 gallon tank that has the base size of a 20 long but a little shorter so it holds 15 instead of 20 gallons. However, I don't exactly have a job yet (I've been looking) and I can't afford to do that at the moment. Would it be a bad idea to move the axolotl to a 10 gallon until i can get the tank i want?
Substrate
I don't know what to do for substrate anymore. I was thinking of sand, but then i read somewhere that you can't use sand with axolotls. Something about sand burn? I've tried looking for more sources to confirm it, but I can't seem to find anything. I know I shouldn't use sand while it's still pretty small, but once it gets a little bigger. Do you think i could use silicone to stick some gravel to the bottom of the tank? I prefer the way gravel looks to sand, but I don't want to risk compaction.
Cycling
I also want to cycle the tank before moving it in. I have an established fish tank that's been up and running for over a year, can I use some of the substrate from the tank to help cycle it faster? Like take gravel from it and move it to the axolotl tank until the water parameters look good. Can i use one of my goldfish to cycle the tank?? I was thinking of moving some substrate and a fish to the new tank until it's good and then moving the fish back to the og tank. I really just want to make this as quick and easy as possible.
Timing
I'm moving to college in about 3 months. I think I'll be moving into the dorms around the middle of august. Should I even bother? I feel like if I'm moving so soon, I should just wait it out. I feel like the 10 gallon would make my baby happier than a tub, but I'm honestly at a loss.

Sorry for the wall of text, I just want to cover all my bases. I want to keep my axie happy. I love it so much and i'd be devastated if i did anything wrong and hurt it.

 

[JoshBA]

A 10 gallon is fine for your axolotl during its juvenile stage. I believe that 15 gallon glass tanks are also sold as a standard size, but perhaps these are less common now.

Fine grain sand is perfectly fine for axolotls. Silica sand, due to natural erosion, is not sharp so burning is not an issue. Most anti-sand sentiment on here stems from the bare-bottom tank dogma, which trades easier cleaning for a loss of surface area for beneficial bacteria. Both are good options in my opinion, and will depend on your aesthetic/maintenance preferences. Silicone+gravel can be done, but may look somewhat awkward.

Certainly. Adding some old filter media/substrate to your new tank is a good way to inoculate with nitrifying bacteria. A good way to cycle would be to add waste items rather than a live fish. This could be fish food, or even waste that you clean out of the axolotl tub. I also always recommend adding lots of fast-growing plants to create a good nitrogen sink. Not the expensive and slow growing annubias and Cladophora balls. But rather species like Vallisneria, hornwort, and anacharis.

Sorry I'm not sure what you're asking with your last question. I think that a cycled 10 gallon would almost certainly be less of hassle than daily 100% water changes with a tub, and would be a much better long-term enclosure for your animal.

 

[entirely em]

A 10 gallon is fine for your axolotl during its juvenile stage. I believe that 15 gallon glass tanks are also sold as a standard size, but perhaps these are less common now.

Fine grain sand is perfectly fine for axolotls. Silica sand, due to natural erosion, is not sharp so burning is not an issue. Most anti-sand sentiment on here stems from the bare-bottom tank dogma, which trades easier cleaning for a loss of surface area for beneficial bacteria. Both are good options in my opinion, and will depend on your aesthetic/maintenance preferences. Silicone+gravel can be done, but may look somewhat awkward.

Certainly. Adding some old filter media/substrate to your new tank is a good way to inoculate with nitrifying bacteria. A good way to cycle would be to add waste items rather than a live fish. This could be fish food, or even waste that you clean out of the axolotl tub. I also always recommend adding lots of fast-growing plants to create a good nitrogen sink. Not the expensive and slow growing annubias and Cladophora balls. But rather species like Vallisneria, hornwort, and anacharis.

Sorry I'm not sure what you're asking with your last question. I think that a cycled 10 gallon would almost certainly be less of hassle than daily 100% water changes with a tub, and would be a much better long-term enclosure for your animal.

Thank you so much ! I really appreciate your answer you're a lifesaver

 

[AMurry24537]

To be clear, the "10-gallon for a juvenile" really only applies as long as they are less than 5 inches long.

 

[axolotl nerd]

To be clear, the "10-gallon for a juvenile" really only applies as long as they are less than 5 inches long.

i highly suggest at least a 20 gallon long. mine has been in a 10 gallon for far too long, and i’m awaiting a 20 gal to arrive soon. your axolotl will very soon outgrow a 10 gallon