Hi thanks all. Cgr I thought that might be the case but these are the new autoflower nutes. Thought the low recommended pH might be to help with cal mag issues or something. Do you think it could be because of light mix soil?
Hello,
I do not think low PH helps with calmag defficiencies and they do not know what soil you would use.
Nutrients are available in different ranges depending in what form they come. Only manufacturer knows what is put in and only they can recommend, especially if product is new and there is not much experience with it around. Roots like acidic soil but nutrients become less available when acidity rises, if not chelated. Maybe Dutch Pro uses chelated stuff and PH is not so important, who knows. But generally, 5,8 to 6,5 is recommended area.
Mostly ph goes down with time in light mixes, but that depends on what is inside. If limed, ph does not drop so much or even rise.
I would go with ph 6,5 for two reasons:
- ph in soil will most probably drop with time
- to use as little acids as possible, because they accumulate in soil and make it more acidic in the future.
Do not forget PH is one of the toughest problems in growing, so you will most probably not get simple answer to your question.
Good Luck!