pH Down Calculator for Hydroponics
Acid Dose for Nutrient Solutions
Example water pH adjustment calculation
This worked example shows how the calculator estimates the amount of acid required to lower water or nutrient solution pH under typical hydroponic or fertigation conditions.
Example input data
- Acid type: Nitric acid (HNO₃)
- Acid concentration: 67%
- Water or solution volume: 100 L
- Water alkalinity: 180 ppm as HCO₃⁻
- Current pH: 7.8
- Target pH: 5.5
Model assumptions
- Alkalinity expressed as bicarbonate (HCO₃⁻)
- Target pH is lower than current pH
- Typical irrigation water buffering behavior
- Uniform mixing of acid into the solution
Calculation result
Calculated values below apply to the specified total solution volume.
Acid Adjustment Result
The table below shows the required acid dose to reach the target pH. Because this acid contains nutrients, the additional nutrient contribution is also listed.
| Parameter | Value |
|---|---|
| Acid name | Nitric acid (HNO₃) |
| Acid volume | 16.07 ml |
| Reservoir volume | 100 L |
• The calculated acid dose is for the specified volume of water or nutrient solution only.
• Calculations are estimates based on the provided alkalinity and pH values.
• For best results, add acid gradually, mix thoroughly, and re-measure pH before adding more.
• Water chemistry, buffering capacity, and temperature may affect the actual pH response.
Nutrient Contribution
| Nutrient | Added (ppm) | Total mass |
|---|---|---|
| Nitrogen (N) | 35.66 ppm | 3.57 g |
• Nutrient values represent the side contribution from the selected acid.
• ppm is the relevant unit for nutrient balance in tanks and hydroponic systems.
• Total nutrient mass is useful for open-field fertigation and nutrient budgeting.
This example represents an estimated calculation. Actual pH response may vary depending on water chemistry, buffering capacity, temperature, and mixing efficiency. Always apply acid gradually, mix thoroughly, and re-measure pH before adding more acid. This calculator is intended for water and nutrient solutions only and is not designed for soil pH correction.
Control Your Water, Optimize Your Yield
Calculate acid doses, manage pH, and balance nutrients with precision tools
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Frequently Asked Questions
- Water and nutrient solution pH directly affect nutrient availability, root uptake, and overall plant health. High pH can cause nutrient lockout, especially for iron, phosphorus, and micronutrients, leading to deficiencies, reduced growth, and lower yields.
