I agree with Tom, minimum 3 ft wide, other wise at maturity it will be scraping the sides to turn around, in actuality a pool of "minimum" 8ft long by 4 ft wide would be better
100% agreed, however I can say if you care for it well, a 3 foot tank will ultimately be too small. For size reference (she was 27”) and was in a 96”x48”
This fella is 18” and in a 96”x36” tank and makes it look small.