Soil pH: The Gatekeeper of Nutrients

Nutrients can be in the medium yet unavailable when pH drifts. In soil, 6.2–6.8 keeps calcium, magnesium, iron, and micronutrients in their sweet spot. Coco and hydro prefer 5.6–6.2. When pH wanders, multiple “deficiencies” appear at once—classic lockout.

Invest in a decent pH pen and calibration solutions. Rinse probes with distilled water after use and store them in proper storage solution. Paper strips and drops are better than guessing but lack precision when you’re troubleshooting finer issues.

Test your input (nutrient solution) and your output (runoff). If input is perfect but runoff is far outside range, your medium is steering pH. In soil, runoff can lag behind changes; watch trends across a week, not a single reading. In coco, runoff responds quickly and mirrors root-zone reality.

Use pH up/down in tiny increments, stir thoroughly, and recheck. Big swings shock roots and microbes. In living soil, lean on gentle nudges: quality compost, balanced mineral top dressings, and carbon sources. Over time, healthy biology buffers pH better than constant chemical corrections.

• Iron “deficiency” on new growth at high pH.
   
• Magnesium “deficiency” at low pH, especially under strong LEDs.
   
• Calcium issues on fast new growth when coco is fed too acidic.
  Before adding bottles, fix pH and observe for 72 hours; many symptoms fade without extra inputs.
   

Salt systems: mix, set EC, set pH, feed to mild runoff, and log. Living soil: avoid chasing a number—water in at 6.3–6.6, keep moisture steady, and let microbes moderate the rest. Either way, a simple spreadsheet note of date, pH in/out, and plant observations creates patterns that save harvests.

If pH is badly off, perform a gentle corrective flush with stable, pH-balanced water until runoff drifts into target range. Resume feeding at 50–70% strength, observe tips and color, then climb back carefully.