Quickly cross the dangerous pool was a mission that Jak and Daxter completed to obtain a power cell in The Precursor Legacy. Jak collected another power cell, after discovering it past an electrified pool of water.
After getting the power cell from "Reach the center of the complex", head into the next room with the bullys and from there take the left path. You will enter a room with a double lurker, take these out first and then press the switch in the center. Three platforms will rise from the electrified water allowing you to get to the power cell at the left side of the room.
Take care of the fact that there's a timer and it is short, jump across the platforms as fast as possible. Don't bother spin kicking, double jump will do the trick. Using a roll jump to reach the ledge is useful too.