Ok, this is it, it differs from the subject some, but you should get the point about the small tanks.
I have a story for you about a wonderful turtle I had and 3 of his friends. 10 years ago, my dad told me to close my eyes and hold out my hand when he came home from fishing. I did so, and when I opened my eyes, a cute little turtle was sitting in the palm of my hand, a red eared slider named Speedy. I put it in our 20gal. aquarium. We found out that he liked live goldfish so that's what he ate. He was moved into a small fish bowl because he was snacking on my dad's fish.
A couple years later my dad came home with another turtle, a yellow eared slider he had caught, named Chomper. He was put in another bowl because Speedy bit his leg.
Then we got a 10gal. and put both in together, they got along. About 4 years later my dad caught 2 more, another red eared, Sparky, and the younger mud turtle, Mudslide. We got a pond but it didn't work out. Speedy and Chomper had formed a bond, so had Sparky and Mudslide, they were in 2 separate 10gal.
Then we gave my rabbits to my cousin, she had a pond in her bathtub, which gave me an idea. Then I had 4 turtles in my bathtub, about 75gal. Now Speedy was huge, about 12" when in full display. Mudslide came down with an illness and died.
There is a huge lake nearby called EdgeWater, I said I was gonna let those turtles go many times before, but I never did. Spring had started, I think it was this past March. EdgeWater is a turtle breeding ground and paradise. Losing Mudslide made me realise that I didn't want these turtles to die in captivity, it seemed wrong.
I took the remaining 3 to Edgewater. I let Sparky go and he was off without a second glance. Chomper, 6 years old, lokked back briefly and was off.
Speedy was different, I gently put him in the water after 10 long years of friendship. He looked at me, his eyes boring into me, and I could swear he spoke, "Thank you, and I will miss you" He was happy that he was free, in spite of our friendship, he was free, and he was happy. It is much like keeping a tang in a small tank, no matter what relationship you have, or how hard you try to give them a good place.