u think the 6.0-6.3 during veg is the culprit then yorkie
Yes mate, you're not supposed to feed a different PH depending on veg or flower.
Because it is not possible to get all nutrients uptaken 100% across the board the idea is to get the best of both worlds as per the chart I posted yesterday.
In soil that is at a PH of 6.5 (I stress that some plants/strains may be a little finicky but there's not much in it).
And in hydro it's at a PH of 5.8 (again, plant and strain dependant).
The PH will change throughout the grow as the plant takes up different nutrients, the key is to periodically test the run off PH and as it changes you alter the feed water PH in order to keep the rootzone PH in the sweet spot.