Just wondering, this hasn't happened yet, but lately I've seen my turtles swim faster at times and bash into the glass of my tank with their shells, it's not an aggressive hit, but I do hear clunking against the glass occasionally, can turtles be strong enough to crack the glass if they rammed at it hard enough?
I currently have a 90G tank where the thickness of the glass is about 1 cm.
My turtle shell lengths are 10, 8, 8, and 7 (in inches).





