this photo told about a year ago
and this one year after
can you see that ? the smaller one much much bigger than the bigger one after a year, when they live together and everything just the same but so much different after a year
They grow at different rates, my smallest radiated a couple years ago is now my biggest. A member of this forum tolm me that males seem to grow slower than females.
With good heat, and daily fresh food they can grow rather fast. Some faster then others even at the same age, so it's hard to tell exact age just on size.