Hi Zweibel,
6.2-6.5 is absolutely perfect.
What I can say is, the moore dead material you have in the soil, the moore pH fluctuations you'll have. I'm having the same situation at my actual run, especially at the Purple Haze.
My mix was 15% perlite, 30% coco coir, 55% Soil. Next run I'll reduce to max 30% of the inert materials (15% coco, 15% perlite)
Hope this will help.
Cheerz mate and good luck.
OimRausch