I've mixed coco with potting mix or mixed it straight into the ground like peat moss to my sandy soil and it worked fine.
I also rarely check my Ph in my well water and have never checked the Ph of my run off water when growing straight in the ground.
I've used plenty of expensive nutrients but my best harvest last year was from a plant transplanted straight into sandy soil. My soil amendments consisted of cheap potting soil mixed with sandy soil, worm dirt from a commercial nightcrawler business near my house, crushed egg shells, fresh urine, 1 bag of composted cow manure from Walmart, fresh goose manure from my yard, deer manure from my yard. Unsulfered molasses, Epsom salts, banana peels.
Plenty of things you can use for your nutrients that you can get cheap or for nearly free just about anywhere. I live on an island, I have ready access to fish I could use as fertilizer. Fresh water seaweed floats up on my shoreline every Summer I could pile up and compost with grass clippings. Kitchen vegetable scraps, wood ashes from burning brush and leaves. Usually I dump my ashes in the leaf piles I remove from my yard every Fall. Small amounts can be used in your soil growing straight in the ground.
When growing in pots I used Fox Farms Happy Frog soil, Fox Farms Trio, Fox Farms Beastie Bloomz, Cal-Mag and ph down to get the correct ph. With all that it seemed my two plants growing straight in the ground did better with less care.
