Hybred turtles

by Fallon
(Hann, Wyoming, USA)

I currently have 5(3 red eared slider, 1 peninsula cooter, and one red bellied slider) aquatic turtles living in the same large tank. My two largest are only 9 months old but have been showing some breeding or dominance habits (One of them is getting long nails on his?? front feet) I have read that turtles can breed outside of their genus but also that they need the proper habitat to do so. Is this true...will they breed , but also can I keep them from doing so with out actually seperating them?