My wife recently bought a water Lilly from lowes, hit or miss I know. However, I was curious as to how long it should take for one to begin to show signs of life.
It should show some signs of life when you took it out of the box? If not, hopefully the bulb is still alive and it will take off once you get it into a warm, sunny pond.
It should have had green on it when you took it out of the package. Waterlilies aren't actually bulbs, they should not be dry and lifeless. Their growing points should have green growth.