pH and EC Explained: SA Beginner Grow Guide 2026
James MokoenaIf you are growing cannabis in South Africa and not testing pH and EC, you are growing blind. Most nutrient problems - deficiencies, lockout, yellowing - come from incorrect pH or over-feeding. These two numbers explain 80% of plant problems.
What Is pH and Why Does It Matter?
pH measures how acidic or alkaline your water and nutrient solution are. Cannabis can only absorb nutrients within a specific pH range. Outside that range, nutrients are physically locked out even when present - this is called nutrient lockout.
- Soil pH target: 6.0-7.0 (ideally 6.2-6.8)
- Hydro/coco pH target: 5.5-6.5 (ideally 5.8-6.2)
- South African tap water pH is typically 7.5-8.5 - always adjust down
- Use pH Down (phosphoric acid) to lower - available at grow shops
What Is EC and Why Does It Matter?
EC (Electrical Conductivity) measures total dissolved salts in your nutrient solution - effectively, how strong your feed is. Too high EC causes nutrient burn (brown leaf tips). Too low EC means the plant is underfed and growth slows.
- Seedlings: EC 0.4-0.8
- Veg: EC 1.2-2.0
- Flower: EC 1.6-2.4
- Late flower/flush: EC 0.5-1.0
Our pH/EC Meter Combo includes a calibrated pH pen and EC/TDS pen - everything you need. Available at BlomSupply with nationwide delivery.
