Introducing my adult axolotl to my juvenile axolotl

[KirbyandMudkip11]

Hello! So I recently just got my second axolotl Kirby! He’s a dirty leucistic and is about 5 inches. I was hoping to move him in with my adult melanoid axolotl Mudkip (8.5 inches), but I’m nervous. Should I wait until Kirby gets bigger?

And how long should I wait to add sand with Kirby? I’m so anxious I’ve never owned an axolotl this young before
(I used the phone measuring app measure them so I am unsure how accurate it is)
Thanks

 

[wolfen]

it is always better to wait until the smaller/younger axolotl is near the size of the larger/older axolotl and cannot be confused with food.
average size before adding sand tends to be around 5 inches.