Original sentence: The Halibut is the largest of all flat fish, with an average weight of about 11 - 13.5 kg (25 - 30 lb), but they can grow to be as much as 196 kg (431 lbs)
Edited sentence: The Halibut is the largest of all flat fish, with an average weight of about 11 - 13.5 kg (25 - 30 lb), but they can grow to be as much as 211 kg (431 lbs)