your question rather generalized..... Theres factors like how much, how often, and what you feed them. how big their enviroment is, etc...their genetics is a great factor, more so in a "pond spawn" where all able fish are involved. multiple egg & sperm donors make for a much more varied gene pool. i have now,from this years spawning, and in the past, have had the fish (fry) from these" pond spawn"s vary quite a bit ...the smallest still just in the 2" range to the largest at over 5" already..