Cohazard;3204113; said:Wow they still have em' at 7" that's cool, I bet you have a lot of aeration or surface movement in the tank.
With high oxygen it takes longer, with lower oxygen, not as long, truth is it varies so much that I couldn't give you a better answer. Some even have small stubs of the externals when they hit 12"!
benzjamin13;3204392; said:like Serg said...it varies. I have one at 6" that still has one and another that lost it's at 4"