Here's why:

* Water Temperature and Absorption: Orbeez absorb water through osmosis, a process where water moves from an area of high concentration (the water) to an area of low concentration (the Orbeez). Warm water molecules move faster, which might seem like it would accelerate absorption.

* However: While warm water molecules move faster, they also tend to hold onto each other less tightly. This means they're less likely to leave the water and enter the Orbeez.

The Bottom Line:

* Cold water is generally considered optimal for faster Orbeez growth.

* Warm water will still allow Orbeez to grow, but the process might be slower.

Let me know if you have any other questions!