flushing plants

How long before harvest do you start flushing your plants, What i have heard you start doing two wk befor harvest using 3 gallon ph'd water to 1 gallon of soil. Do you do this every day or do it on your regular watering days. growing low ryder 2. thanks for all the help.

flushing the soil out helps get rid of any salt build up, I would do it every third or second day dipending how quick it dries out.