you should keep watering all the way until harvest but you can stop a couple days early if you want. two weeks is too much though. you should start flushing your plants 2 weeks before harvest
When you harvest, no water the day before or even 2 days before. Also make sure you harvest/chop down before the lights come on after the 12 hr dark period. This will keep alot of the salts,etc down in the roots.