Frog replacement hook size

I have a Z man frog 2.25 that my son has been using, getting plenty of blow ups but few hook ups. I went to bend the hooks out some and when I did, the hook snapped smooth  off! I have seen that there are replacement hooks for frogs that are made by some top hook companies. It seems that 3/0 and 4/0 are common and then it jumped to 6/0. Does anyone know what size I should consider to replace the broken hook?

On a different note about his not hooking up, I got him a Med Hvy fast in 6'6'' because of his size. I put a 7:1 gear ratio bait caster on it with 65 lb braid and He has  a pretty strong hookset. I think maybe he is waiting a tad too long so I have been working on that part of it. 

Any advise on the hook replacement or frog fishing in general is welcome.

Thanks