Sand in freshwater?

[xfactor6699]

I have a friend that had 4 cray in his tank and they do fine...he has lots of rock caves that they can hide in..he might have just got lucky

 

[alLexX]

what kind of crays(some are more tolerant than otheres),and what tank size?also,how big arethe crays?

 

[xfactor6699]

75g tank and they are 2 red 1 white and 1 blue lobster and they are about 2'' maybe 3''

 

[alLexX]

my cray was friendly untill she got to about 3 1/2-4",then she started killing.