In the heroic race, the pool is the maximum number of items available to collect at the very start of the mission.
The pool always starts off full
Once you start emptying the pool, new items will fill the pool according to the wait time
You cannot collect any items if the pool is empty - you will have to wait for the pool to fill back up
the pool must have at least one item in it to collect.
use the lap information and remember details about the pool, the game will not tell you this information.