Been offered one of these really wanting a care sheet only thing I am not sure about is tank size. I have a spare 5 gallon exo terra if that's big enough
Rufilata and Ornata are the biggest 2 yeah, The metallica is one of the smaller ornamentals, youll be lucky to see 7 inches when mature if female. As with most ornamentals the males have a similar span but are dead skinny looking compared to females. A 12in cube will be fine.I think that will be ok. I know with my P. ornata I was recommended to get the 30x30x45 but then I think Ornata grows to be the biggest by a noticeable amount.