how can u compare a test kit to a ph pen thats accurate upto a 0.02 ph ? and i find that unless u have a really good eye matching skills your never gonna get it to the point u want it
Does someone go round probing the soil next to each plant in the world to make sure it's ph is accurate to within 0.02? Weed will happily grow in ph between 5.5 and 6.5 approx, and I've grown without pH down/test kit which meant pH was around 7.. Plants were fine. You simply don't need to be that accurate with your pH, though fine tuning can help.
I can eyeball colours without a problem to within around 0.5 of actual I'd say, and the fact I haven't had a ph problem backs that up. Pens take out the guesswork and as has now been said a few times they are most accurate.. But just look at your current issue; your ph is out by around 1 whole point, and your only way of know is because you're clever enough to recognize that your tap water ph can't be that low.
Seems to me you should recalibrate in the ph 7 fluid and try again.
I can't get freaking pics from my phone to my comp, stupid iPhone is recognize in iTunes and not in windows. Reinstalled drivers and software and tried a few different tricks, even resorting to restoring factory settings in the phone... Nothing! And now I have to jailbreak again and get all my apps back - and it means my computer is fucking up AGAIN even on windows 7.