GMSgrowsanswered grow question 3 years ago Check the soils ph and make sure you calibrate your ph tester properly. When calibrating, do 7 first then 4, after that check 7 and 4, until you don't need anymore adjustments to either of them from going from 7 to 4. It could take 3 or 4 times to get your pen to read 7 and 4 with no more adjustments. Cheers