Question
Can you tell me or refer to someone who would know how long it will take for
my ryukin's hump to develop, he is a little over one inch long now and i was
just wondering how long it may take? thanks

Answer
It will become more prevalent as the goldfish grows older.  A one inch goldfish is still pretty tiny.  I would say that by four inches, the fish should have a pretty obvious hump behind the head (up to the back).  A ryunkin may take 2 to 5 years to grow to 4 inches depending on temperature, water quality, food, and more.

Good luck!