Thanks once again!
I actually did it 5 minutes ago putting my 3 sprites in a family, creating the family every 5sec (that creates 1 of 3 sprites at a time) and used behavior fade (duration 5sec) for despawn.
That way, a random one is created every 5sec right after the previus one despawned!
I know its not the right way, but since it works, im keeping it.
Thank you again for your help.
People like you keep this comunity healthy!