Hal, you were one of my inspirations when I started the coco journey and I am glad you answered so many questions when I was the one asking. I will probably pick up some ripen when I run out of Clearex.
Personally I adjust my PH to 5.8/5.9 and it works, but Hal does differently and has great success so I imagine that either will do.
With drip temps, I don't believe that it is as detrimental as a full on hydro set up, but never the less, roots love cool water feedings even when in soil, but I would say that what ever temps you can get away with in soil can be workable in coco. Beyond that I can't say much, except for maybe one thing, one grower who helped to persuade me to try coco who is a mod on another board was converted him self when he went to his brother and laws house and saw his coco grown plants thriving in Australian temps while he himself was having a terrible battle with DWC.
Thanks for stopping in folks.
Adieu