Water Alkalinity Adjustment & pH Up Calculator
Hydroponics, Irrigation, and Fertigation
K2CO3 | KHCO3 Dose & Buffer Capacity Calculator for Hydroponics
Safety Tips & Recommendations
- This calculator provides theoretical dosages; always verify alkalinity on-site.
- Adjust alkalinity gradually; adding too much K₂CO₃ or KHCO₃ at once may raise pH excessively.
- Potassium salts increase both alkalinity and potassium concentration; consider crop nutrient requirements.
- Measure water hardness (Ca²⁺, Mg²⁺) before large-scale application; high Ca/Mg can precipitate with carbonate.
- Dissolve salts completely in water before application; uneven distribution can cause localized pH spikes.
- For RO (reverse osmosis) water: while recommended for hydroponics, it removes nearly all buffer capacity, so water should be re-buffered to maintain stable pH.
- Wear gloves and goggles when handling concentrated powders to avoid skin and eye irritation.
- Keep accurate records of dosages and water tests for repeatable, safe adjustments.
Example Calculation
Input data:
- Salt: Potassium carbonate (K₂CO₃)
- Water volume: 250 L
- Current water pH: 5.1
- Current water Alk. as CaCO₃: 10 mg/L → Target water Alk. as CaCO₃ 60 mg/L
- Use RO: yes
- Ca: 1 mg/L
- Mg: 3 mg/L
Result:
To reach a target alkalinity of 60.00 mg/L (as CaCO₃), you need to increase alkalinity by 50.00 mg/L (as CaCO₃). Using Potassium carbonate (K₂CO₃), the following adjustments are required:
• Required dose: 69.04 mg/L
• Estimated final pH: 7.81
• Potassium (K) contribution: 39.06 mg/L
For a total water volume of 250 liters:
• Total salt required: 17.26 g
• Total potassium (K) added: 9.77 g
Results are algorithmic estimates. Actual alkalinity response may vary depending on water composition. Add the material incrementally and re-check values to ensure precision.
