He's using an organic PH down (citric) .. I've always thought that it doesn't stabalise well .. so my thinking was to get it down from 8 on one day, and check it the next.
I don't do PH at all - I just let the biobizz soil do its thing! I'm freed from the shackles of meters and technology (umm other than the LED light .. and everything else in the tent
)
Reading the Biobizz official statement, Verkhond will be fine to adjust PH after adding nutes (and think that's what i always did with the coco grows)
Although interestingly .... when i was monitoring EC and PH .. I'd add the feed first ... check the EC .. it's all good ... ccheck and adjust the PH .. and the PH adjustment would adjust the EC again ... so the merry frikken dance continues (if you're doing a stepped EC climb) .. so in the end i reationalised that the PH down has no nutritional value, so the extra EC could be disregarded.
But as i say, i'm free from that kinda level of commitment now