PH is best in my opinion between 5.9 and 6.1. If you ad MgSO4 (epsom salt) it chemically combines with N at a ph under 5.8. I add about 50 ppm of ions every two to three days with my watering. If you got to raise it back up baby organic soy formula is amazing. It will raise the ph for 24 hours till bacteria and micro organisms counter and raise it up naturally. They sell it with lipids or without. Lipids which are found in breast milk help retain moisture and slow transpiration so I would recommend no lipids. Iron is good.

One love
c