Hmmm, from a psychological viewpoint, I beg to differ (here I go again

).

Turtles in captivity, in my opinion, are more sensitive to stressful conditions than a wild turtle for a lot of different reasons. I'll list just a couple...
1) Health - Wild turtles get a much more natural and varied diet than captives do. They also get more exercise, fresh air/water and sunlight.
2) "Street smarts" - Wild turtles know the ways of the great outdoors. They know that they can escape a threat. Captives only know that there is no escape from a threat in their confined cages. They will get caught and picked up. I would imagine they would be more likely to panic outdoors.
3) Stress - Wild turtles are relatively stress free, able to live by their instincts successfully and relatively undisturbed. Captive turtles live by our grace alone, unable to fully exercise their own instincts. If we can provide them with a safe comfortable and healthy place to live, they can adjust and be happy. But I think that because of so much dependance on us, they would be more stressed in an unfamiliar environment (like a large swimming pool with people splashing around). But just like people, I'm sure some turtles are more resilient than others.
He he, I'm no turtle shrink (although I pretend to be one sometimes

) but these are just my thoughts on the matter. I liken it to a similar situation with a human. If you took a baby human and raised them in a very sheltered and enclosed environment, they would be relatively happy if provided with their basic needs and desires. But if you suddenly introduced that person to the real world, they'd probably go into shock.
So back to the swimming pool thing...I know a lot of people use Baquicil (sp?) instead of chlorine nowadays. Is that actually a salt solution? That's an interesting thought, because I believe the RES can adapt to brackish water conditions.