Optimal pH for solution, when growing in 70% Promix BX, 30% perlite.

6.3-6.5

Hi canabis Pflanzen brauchen je nach Phase einen anderen PH wert. Wenn sie keimen und in den ersten Tagen-Wochen einen PH wert 5.8 wenn sie älter werden und in die Blüte Phase wechseln steigt auch der ph wert auf 6-6.2 je mehr sie in die Blüte gehen desde höher der ph wert bis 6.5. Das hat was mit der besseren Aufnahmen der Nährstoffe zu tuhen die sie in jeder Phase brauchen.

And my range would be 6.3-6.5 , if i would treat any medium as soil. Does magic in my own opinion.

Years ago , i was growing in pro mix hp, bags looked with orange stripe, not blue like they pack now. I treated it as soil. It was very potent, started to feed on weeks 3-4 only. Later that brand vanished from UK market. So i tested fox farm soils and falled in love with biobizz all mix. I asked them here about ph range. If you use Instagram - ask them there or write email. Roberts is one of most sponsored persons here. He grows a lot in coco, but treated pro mix as soil, for me personally, it speaks huge volume ;)))

I just did a Pro mix HP bag grow. I used 6 to 6.5 range. Worked great.

It's about the type of fertilizer you use, not the physical substrate that holds the water. The charge that comes with BX or HP bales is ~1EC. It's very low and it'll be exhausted the first week, so it really does need fertilizer from day one despite the charge of elements. I'd suggest shooting for 6. this gives a little leeway on each side if things go wrong. If you go a couple tenths lower or higher, nothing bad will happen and you stay near the acidic end of a good range which should improve results compared to more alkaline pH. If you treat it as a soil and use 'soil' fertilizers, 6.5-6.8 is what you want because it helps with availability of N, which is not necessary for ingredients that provide N in hydro/soilless fertilizers. The molecules that deliver N need microbes and other forces to break it down to be plant available. This difference is behind the 'why' even if i can't explain in detail. The ingredients for soilless fertilizers are 100% dissolved and 100% plant available upon going into solution.

If promix is like biobizz I'd go 6-6.5,