5x2x2 is to small you need a 7x3x2 min tank size
they do eat meat you need to do some more resurch
their main food is veg but they do eat meat
if they eat river shrimp in the wild what is the diffrence between river shrimp and prawn
mine was fine with fish when the arowana was in the tank as the aro used to keep the FRT in its place but 2 weeks after i sold the aro the FRT started to kill fish for fun not to eat them just to kill
turtles and fish just dont mix
5yrs and only 8inch their is something wrong their
dont get me wrong they are a great turtle but not with any fish you are not scared of losing
the way the cycles works is you are right amonia-nitrite-nitrate
but the FRT lets out so much other crap into the water that you just cant test for you dont never see any large piles of crap from the FRT
good luck i hope you dont lose anymore fish