Fishing: Big Red Nimble Fish, please help

Hi guys, I wonder how can I make the Big Red Fish agile for Agathion Bracelet Little Angel, is that before buying potions red GOD and skill level between 19 and 21, it could catch Big Red Nimble Fish, but now the truth I am not able to get them out I'm pretty lost with this issue, I asked goldfish agile big for the Agathion at the guild member fishermen no longer appears these potions, as I can do to get these fish? experience skill I need to achieve the capture of Big Red Nimble Fish now or need other types of fish? thank you very much from and for your time, and hopefully get some help. ;) Greetings ...