Psyphish believe me I am right there with you, and the only thing that I can think is that my PPM meter might be off, but I don't think so. Also I believe that plants can not only handle but thrive in higher PPMs when all of the other factors are ramped up, like lumen output, temp, relative humidity, oxygenated root zone and so on. So at this point I am stopping trying to guess if it is right or wrong and just letting them grow lol and they seem to be doing amazing so I really am just going with it! These plants have had the highest PPMs I have ever seen throughout the whole grow so it really didnt surprise me when they were able to handle the 4k. These things are beasts!