strainray ? i guess u talking stingray , better dont try, Fh may kill ur stingray, i have that happen before the Fh bit off the stingray the eye, and even the tail too, and depending ur Arow how big , but even okie, not 100% safty forever, from you-tube u saw the Fh i guess from the smallest baby ,until grow fully size stay together ,they knew each other, so less chane to fright, otherwise , u may loss ur fish one day but dont cry! good luck!but i saw on you tube have alots can stay together with strainray and arow with flowerhorn too,,,,,,,
my strainray have almost 10" and arow have 15"....
but thks for everyone ....