What is the best octopus circle hook size for catfish?

ok, i herd circle hooks work great so i thought about switching, i been using snelled hooks size 4/0 or u can say j style hooks, so which size of circle hooks is about the same size as the snelled hook size 4/0(j style)? catfish around my pond are around 2-5 pounds, not so big. i know, im only 15 but still alot to learn, its also because im buying it on amazon, so i cant actually see it in real life, so i need suggestions. i saw size 4/0 in a video of circle hooks, and they look way to big. i saw a size 6, and it looks good, but i need more opinions, thx for all answers!