hi...

Question
umm, is it okay that I can let my red-eared sliders into a lake and what if they're in a bathtub, thats alright, right?

Answer
I am not sure what you are asking.

Releasing them into a lake is a bad idea on several levels. They probably won't survive, and if they do they will mess up the local population.

Keeping a turtle in the bathtub is OK, if you can keep the water clean (well-filtered)and warm (75-80F), provide a good basking site, and deal with the Salmonella problem before using the tub for humans again.

Turtles need decent homes. You can learn more about turtle housing, diet, etc. at a good site like http://www.redearslider.com

Good luck!