Good question, and I don't want to mislead you- I do not know if there is a difference that is dependent upon delivery method, but personally, I would actually hand-water soilless right AT 6.5, making sure my nutrient solution was correct. I'm not someone to ask on this one, since you can see in my grow log that I jsut royally fucked up a soilless (promix) crop by forgetting to check my EC and as a result never thought to add CalMag to it