Illness/Sickness: R.I.P

My Henry died yesterday afternoon. Too much stress? i put him on a nightcrawler diet.... i also changed his water and tank arrangement... too much at once? i dont want to make the same mistakes on my next one.... help me out? He was approx. 2 inches long... was really healthy just the night before. i was handfeeding him tadpoles. but switched to nightcrawlers, and he was due for a tank change so i knocked that too... when i put the tank back together, i changed his arrangement and gave him a new hide.... the water looked great, but i could tell he wasnt too happy... which he always is after water change... so i didnt think anything of it.... he was alive when i woke up and before i left for work... later that day i recieved a call from my roommate telling me he was dead... im very upset... i want to start over but i dont want to make the same mistakes on the next axi.... 15 gal. tank, non-filtered, gravel HELP PLEASE!

I don't think changing the tank arrangement would be nearly enough to stress an axolotl to death. What were the tank parameters? Where did you get the nightcrawlers?

about 24" by 12 or 14"? i did make the water an inch deeper too... room for growth i thought... and the nightcrawlers from petsmart

Where did you get the tadpoles from? I know reptiles sometimes don't show sickness until they're on their last thread, I don't know if its the same with amphibians. It could have been something parasitical or internal that couldn't be easily detected. I'm sorry for your lost

Was he still eating fine? How big was the gravel? I didn't think impaction would kill that quickly but if he was so small it might have.

What were the water paremeters like? Nitrate, Nitrite and Ammonia?

Though I admit I don't know a lot about really young axies.

Get rid of that gravel!
Your new axie will eat it, get sick and die.
Sand or nothing are much better options.
Take a look around the Tank set-ups, filters, substrate sub-forum. It has some really interesting set ups, lots of dos and don'ts, and if you upload a picture people will tell you if and what needs changing.

Tadpoles aren't the best food option as they can transmit diseases.
So your change in diet is a good thing.

I'm sorry you lost him.
It seems unusual that he died so fast, showing only little signs.

what was the ammonia, nitrite, and nitrate? As others have said gravel causes impaction, and tadpoles are known to carry diseases. There's two ideas right there, if you test for the water parameters we might be able to give you a better idea.

When you changed up the tank with new water was there a major tempreture change in the water?

he was eating great! his lil tummy was full! he looked happy before i left for work. and the nitrate was a lil high, when i say lil, i mean it... it wasnt bad at all... nothing i would normally worry about. and everything else was great.... the gravel is huge too... like 5 or 6 times his size... i dont see him choking on that... idk...

there was no change at all... his tank stays at room temp... which is between 64 and 68 degrees 24/7!

i got his tadpoles from an isolated pond at my roommates moms house...

If your going to get another axi invest in a filter, it will make your life much easier and its better for your axi