pH too high?

If you are growing in soil, this pH is fine and not harmful, probably ideal really. This is the range I would aim for when I started growing 35+ years ago, in soil, but must admit that for the last 25 years or so, I rarely check my soil pH and as long as you are sensible with your soil mix, nothing much affects cannabis, she is a pretty hardy plant. Often, if trying to change pH quickly, this will harm your plants more than if you had just left them alone! Nutrient "lock out" in the true sense does not begin to occur until your soil is above 7.5 or below 5.5. Anywhere between 6.5 and 7.2 is ok on soil, with no notable issues or any real need to have everything exact. Your plants will grow just fine. Hope this helps,............. Organoman.