I Have A Cousin Who Is Interested In An Aquarium For His Family...

[Jeremy180]

Hovever, it's a military family and they have to be ready at a moment's notice to move, thus they need a small tank that's easy to move.
Also, they may have to move to a location that has a different water chemistry.
 
So, besides the standard bettas, are there any tough as nails fish or other aquatic animals that could tolerate a tank of about 5-10 gallons, a fairly wide range of water chemistries, and the stress of moving more than once in it's lifetime?
 
I did warn him to not get his hopes too high, here.

 

[SherLar]

   Most goldfish are pretty hardy, and would survive the stress of multiple moves, though unhappily. I would probably recommend a larger tank though. Even a single goldfish will quickly outgrow so small a tank.
   Instead of an aquarium, maybe you could recommend a small terrarium.

 

[eaglesaquarium]

A 20 gallon tall with a black moor might be a nice option...

 

[fluttermoth]

A 20 gallon tall with a black moor might be a nice option...

 
That's a bit on the small side for a fancy goldfish, tbh, buddy. We normally recommend a minimum of 100l/26 US gallons/22 UK gallons.

 

[eaglesaquarium]

 

A 20 gallon tall with a black moor might be a nice option...

 
That's a bit on the small side for a fancy goldfish, tbh, buddy. We normally recommend a minimum of 100l/26 US gallons/22 UK gallons.
 

 
I stand corrected.  

 

[Blough]

I suggest they go for something not aquatic, just because water chemistry changes so much from place to place. If I were your cousin I would get a domestic rat or two. Two because they prefer to live with other rats, and it makes their quality of life so much better. They only live a couple of years, so they aren't a huge commitment, and they are really sociable creatures. We (my family and I) got our first rats about eight years ago, and have learned that the don't bite. They're really cute, and you learn to overlook their ugly tails after a while.