Ahh yes.. the dreaded PH issues... I have always used Sunshine #4... Ph is pretty much perfect for seedlings if you use just plain tap water for the first week or two.. I have a few plants that I am trying in Coco... I have heard it dries really quickly.. which works well if you water small amounts daily (which I HIGHLY recommend!), and the Ph was a little high.. I was reading 6.8.. I prefer between 6 and 6.5 for this type of medium :-)