Burmeseanswered grow question 4 years ago Hi there, It’s because of organic matters in soil.I always have that kind of high pH problems.I overcome that by using RO water and adjust my water pH around 6.0~6.5.You can flush if you want to.I think it will take so long to lower your soil pH and can cause some unwanted problems after flushing.pH can also be rise again later on.So I would like to recommend you to adjust your water pH around 6.0~6.5 whenever you watered and flush only when she is closed to harvest.
Happy growing... ✌️