How long does it take to lose water weight?

I recently had a cheat day and ate about 2500 calories. A lot of salt was included in that. The next day i was up 3 pounds on the scale, and today two mornings later i am still at the same amount. How long does it take for the water weight to come off in your experience. I have been eating back on track and drinking plenty of water. I am just concerned because i am currently participating in a dietbet and need the weight to come off to reach my goal. which i was at before i gained the water weight.