It is possible that is why the eyes are shut. Also if he was in a lake there could have been some pollution that got into his system and that can take a few days to set in.
good filtration (you think fish are dirty?!
Never a truer statement. I typically recommend double what you would use for fish when setting up a turtle tank.
Females are usually a little smaller
???????????? Are you sure, all of my females have been larger than my males.
The other thing that you may wish to watch out for, if you are using a glass tank, chek it frequently. I have had 2 now that were cracked by the turtles swimming into the sides. As a matter of fact, I was just here checking some posts, and I heard some water hitting the floor (at 3am never a good sound). I went out into the living room and saw a nice crack in my 50 gal
turtle tank (I have 2 RES). Just got finished changing out tanks (good thing I still had the old one in the garage.