Second harvest with a DWC setup and I'm not sure what I'm doing. Week 8 and one of my plants is looking close to finished so I started flushing 7 days again. Last night, drained the bucket and ppm was 1200 but I Never fed over 800ppm. Filled the bucket with tap water (150 ppm from the tap) and tested about 12 hours later at 400ppm. So is the plant pushing out all the nutrients? Where is this ppm coming from? Can I or should I change the water more often to keep ppm as low as possible in the bucket? Thanks y'all!