Unfortunately, not likely.

because, 1) they will most likely fight(because of gender or just plain dominance)
2)They grow very large, my female is just going on three and is 7" now. You turt is 5" and will need all the room he can get. 30g is kinda small as it is for Clover.
3) If clover has been solitary most of his life, then he wouldn't take well to another turtle just "popping" in on his turf.
4) Disease and Stress would spread quick in that limited amount of space.
Sorry, I hope that you can find a solution that best helps the turtle. The best I can think of is either a pre-made pond or like Velpacray said a large plastic bin or stock tank.
Good luck
