They give you a range it should stay between . At 6.5 some nutrients won't be uptaken https://goo.gl/images/LGaf8r
'Carpe diem et fumum veriditas'
I know coco is considered hydro. Is peat too? If so, then I should probably reduce my pH level to closer to 6. But I was told by someone with a lot of experience to target 6.5. However I'm open to all ideas.