Calculator Inputs
Plotly Graph
This chart compares achieved ppm across the allowed injector range and marks the selected target ppm.
Example Data Table
| Scenario | Stock volume | Fertilizer | Nutrient % | Target ppm | Recommended setting | Approx. ratio |
|---|---|---|---|---|---|---|
| Leafy greens feed | 20 L | 2000 g | 20% | 150 | 0.7500% | 1:133.33 |
| Seedling feed | 15 L | 1000 g | 15% | 75 | 0.7500% | 1:133.33 |
| Heavy fruiting crop | 25 L | 3000 g | 18% | 200 | 0.9259% | 1:108.00 |
These examples assume full dissolution and use the selected nutrient percentage only.
Formula Used
Nutrient mass (mg) = fertilizer mass (g) × nutrient fraction × 1000
Stock concentration (ppm) = nutrient mass (mg) ÷ stock tank volume (L)
Setting (%) = target ppm ÷ stock concentration × 100
Ratio = 100 ÷ setting (%)
Concentrate used (L) = irrigation water volume (L) × setting ÷ 100
Water volume (L) = flow rate (L/min) × runtime (min)
This method works well for fertilizer injection planning when the targeted nutrient percentage is known and the stock tank solution is mixed uniformly.
How to Use This Calculator
- Enter the stock tank volume and choose liters or gallons.
- Add the fertilizer amount placed into the stock tank.
- Enter the nutrient percentage from the fertilizer label.
- Type the target nutrient ppm needed in irrigation water.
- Add system flow rate and expected runtime.
- Enter the minimum and maximum injector setting range.
- Use the optional safety margin if you want a slightly higher recommendation for field adjustment.
- Press calculate to view the recommended percentage, ratio, tank usage, graph, and export options.
Frequently Asked Questions
1) What does this Dosatron setting calculator estimate?
It estimates the injector percentage needed to reach a target nutrient ppm in irrigation water. It also shows ratio, stock usage, runtime water volume, and whether the selected injector range can achieve the target.
2) Which fertilizer percentage should I enter?
Enter the percentage of the nutrient you are targeting. For example, if you want nitrogen ppm from a 20-20-20 fertilizer, use 20. If you are targeting calcium from a different product, use its calcium percentage instead.
3) Why is ppm treated like mg/L here?
For dilute irrigation solutions, ppm is commonly treated as milligrams per liter. That makes fertigation calculations practical and consistent for greenhouse and garden feeding plans.
4) What if my required setting is outside the injector range?
Your current stock solution is either too weak or too strong for that injector range. Adjust stock concentration, target ppm, or choose an injector model with a more suitable operating range.
5) Does this calculator work for liquid fertilizer too?
Yes, if you can convert the added nutrient amount into an equivalent mass and know the nutrient percentage. The calculation is based on nutrient concentration in the stock tank, not product form.
6) Why does tank autonomy matter?
Tank autonomy tells you how long the stock tank can supply concentrate at the calculated setting and water flow. It helps prevent the stock tank from emptying before the irrigation cycle ends.
7) Should I trust the safety margin result directly?
Use it as a planning aid, not a lab guarantee. Always confirm final injector performance with practical testing, especially when water quality, product solubility, or injector calibration may vary.
8) Can I use this for different garden crops?
Yes. The calculator is crop-neutral. Change the target ppm and fertilizer percentage to match seedlings, leafy greens, fruiting plants, ornamentals, or other garden feeding programs.