when i grew in soil, my ph runoff was "never" where it's said it's supposed to be. i made sure anything i put in/on my plants was ph'd to 6.5. since i didn't see my plant telling me there was a problem, i stopped checking my run-off ph altogether. i always allowed for run-off when watering/feeding. the plant is constantly eating/drinking from the medium. this is gonna cause your run-off ph to seem off. in most cases i'd say ignore it. your plant will tell you when there's a problem.