You're right, if you're dumping nitrogen and what ever else a week before harvest you should flush because you're a fuckin idiot.
Most reasonable people choose to learn how and when to feed. People like you choose to stay clueless. Wouldn't it be easier and cheaper to not overfeed and cause problems in the root zone to begin with. Heres some facts for ya about water clearing soil of nutrients clown.
http://nmsp.cals.cornell.edu/publications/factsheets/factsheet22.pdf
What is Soil?
Soil is one of the three major natural resources, alongside air and water. It is one of the marvellous products of nature and without which there would be no life.
Soil is made up of three main components – minerals that come from rocks below or nearby, organic matter which is the remains of plants and animals that use the soil, and the living organisms that reside in the soil.
You can wash away what the fuckin soil is made of, but still have soil in the pot? You're brilliant. You have to be a troll no one can be that ignorant unless it's on purpose. You should stick to eating paint chips and crayons.
Maybe, I don't know, No shit! If water resets soils ph how do people grow weed outdoors?? Rain water is about 5.5 so how do you suppose the ph stays in range? What ph do grow in? Must be a MF'er for farmers to have to run around with buckets of ph up every time it rains.