Leaves curling... is this clawing?

This is clawing. It usually results from overfeeding nitrogen and your pH is probably out of whack as well. Your diary gives us no information on the nutes you're giving if any or the pH you're maintaining... If you're in an aquaponic set up, you need to make sure the EC is appropriate and maintain a pH between 5.8 and 6.0.... If you've got goldfish and a turtle in there, that kind of complicates matters a lot! They may not like being in as acidic environment as the plant needs.... so I think you're going to have to choose between the plant and the animals... Personally, I'd get the fish and the turtles their own home and concentrate on providing the best environment for the plant... but it's your call! Good luck!