Not advisable even if a 10 gallon is temporary for one turtle and definitely more. They are curious and voracious (especially when younger) and have a tendency to try and eat everything or at least mouth it out of curiosity. There tank is usually set up accordingly. Things like fish, frogs, smaller turtles ect. They are likely to take a bite out of and if too big for them may choke as well. Here's some great turtle sites for you to bookmark.
www.austinsturtlepage.com www.turtletimes.com
www.austinsturtlepage.com www.turtletimes.com