i keep my 5" carapace FRT with 7" disc leo pair & 6" pearl pair, also an 8" Super Red, 2 Red Severums & 2 Tinfoils.
noticed just yesterday dat the tail tip of 1 of the pearl has been chewed up!!! it was just a couple of months back that i had to give away my 4 beautiful leporinus fish coz i saw them chew up both the leo's tail... dont ask me why but taking this past experience, i just went ahead & concluded that this new damage must've been made by the tinfoils!!!
i watched the tank closely & within a few mins realized that the tinfoils were just imprudently swimming about the tank, but it was the FRT that was slowly sneaking up on the Pearl & nipping bits of the tail off!!!
i immediately moved him to a presently empty feeder fish tank & have informed my LFS guy that i wanna give the FRT away ASAP!!!
u make ur call, either the FRT or the Rays!!! Very very very lucky if u get to keep both in the same tank!!!
p.s.
i think it was T1karmann that told me in 1 of the earlier threads that FRT with rays is a ticking bomb!!! i decided to take the risk & now i'm suffering watching my pearl heal!!!