Ozone Dose Calculator for Garden Water

Calculator inputs

Set your water volume, targets, and equipment details.

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Water volume

Batch size in your mixing tank or irrigation loop.

Enter a valid volume.

Volume unit

Conversions are automatic for calculations.

Target ozone concentration

Final dissolved level you want to maintain (mg/L).

Enter a target concentration.

Ozone demand factor

Extra mg/L consumed by organics, biofilm, and turbidity.

Transfer efficiency

Percent of generated ozone that dissolves into water.

Use a value from 1 to 100.

Contact time

Minutes ozone stays in contact before use/discharge.

Enter a contact time.

Safety factor

Percent extra ozone to cover variability (e.g., 10%).

Generator output

Your ozone generator capacity (g/hr).

Enter generator output.

Generator power

Optional: electrical draw in kilowatts (kW).

Electricity price

Optional: cost per kWh for energy estimate.

Notes

Saved in downloads for traceability.

Reset

Formula used

1) Applied concentration

C_applied = C_target + C_demand

Demand covers ozone consumed by organics and turbidity.

2) Dissolved ozone mass required

m_dissolved(g) = (C_applied·V_L / 1000) · (1 + SF)

Converts mg to g and adds a safety factor.

3) Ozone gas required

m_gas(g) = m_dissolved / (η / 100)

η is transfer efficiency from gas to water.

4) Runtime and CT

runtime(min) = (m_gas / G) · 60
CT = C_target · t

G is generator output (g/hr), t is contact minutes.

Tip: If you measure ORP instead of mg/L, calibrate your target using a meter and trial batches.

How to use this calculator

Measure your batch volume in the tank or recirculation loop.
Set a target mg/L that matches your crop sensitivity and goals.
Add an ozone demand factor if water contains organics or biofilm.
Enter transfer efficiency from your diffuser or injector setup.
Choose a contact time before irrigation or discharge.
Enter generator output to estimate runtime and feed rate.
Download CSV or PDF for records and batch consistency.

Example data table

Sample scenarios for comparison.

Scenario	Volume	Target (mg/L)	Demand (mg/L)	Efficiency (%)	Contact (min)	Generator (g/hr)	Ozone gas required (g)	Runtime (min)
Drip loop sanitation	500 L	1.50	0.30	80	10	20	1.238	3.7
Hydroponic reservoir	1000 L	1.00	0.20	70	15	25	1.886	4.5
Greenhouse misting	200 L	0.80	0.10	85	8	10	0.233	1.4
Storage tank refresh	2 m3	1.20	0.40	60	20	30	5.867	11.7
High-demand source water	300 gal	1.80	0.80	55	12	35	5.905	10.1

Examples assume a 10% safety factor. Always verify settings with sensors and crop guidance.

Water quality factors that change dose

Ozone demand rises with organics, algae, and fine solids. This calculator separates the target concentration from an added demand factor so you can budget extra ozone when source water is cloudy or biofilm is present. For example, a 0.3 mg/L demand added to a 1.5 mg/L target increases applied concentration to 1.8 mg/L before efficiency.

Dose math tied to your tank volume

The dissolved ozone mass is based on mg/L × liters, then converted to grams. A 500 L batch at 1.8 mg/L equals 900 mg (0.9 g) of dissolved ozone. With a 10% safety factor, it becomes 0.99 g. This keeps your dosing consistent when you switch between 200 L mixing bins and 2 m³ storage tanks.

Transfer efficiency drives ozone gas required

Only a fraction of generated ozone dissolves. If efficiency is 80%, the 0.99 g dissolved requirement becomes 1.24 g of ozone gas. Dropping efficiency to 60% increases gas requirement to 1.65 g. Use this section to compare diffuser upgrades, injector tuning, and bubble contactor design choices.

Contact time and CT for disinfection planning

CT is a simple performance indicator: CT = C_target × time. At 1.5 mg/L and 10 minutes, CT equals 15 mg·min/L. Raising contact time to 15 minutes increases CT by 50% without changing concentration, which can improve results when you cannot raise mg/L due to crop sensitivity.

Runtime, capacity checks, and operating cost

Runtime depends on your generator output. Using 20 g/hr capacity, 1.24 g of ozone gas needs about 3.7 minutes. The calculator also estimates energy using your power input: at 0.18 kW for 3.7 minutes, energy is roughly 0.011 kWh. Track CSV/PDF exports to standardize sanitation batches across seasons.

FAQs

1) What should I enter for ozone demand?

Start with 0.0–0.3 mg/L for clean water, then increase if you see odor, algae, or filter loading. If you have a meter, tune demand so measured residual matches your target after mixing.

2) Why does low transfer efficiency increase my dose so much?

The calculator divides required dissolved ozone by efficiency. When efficiency drops, more gas is wasted to off‑gas, so the generator must produce more to reach the same dissolved target in the water.

3) What does the CT value mean here?

CT is concentration multiplied by contact time. It helps compare “strong and short” versus “mild and long” dosing. Higher CT generally increases disinfection impact, but practical limits include crop tolerance and system design.

4) Can I use this for recirculating hydroponic systems?

Yes. Use the effective loop volume, not just tank volume. If water is continuously recirculating, consider shorter contact intervals repeated over time, and verify residual levels with a suitable sensor.

5) Why is there a safety factor input?

Real systems vary: temperature, flow, diffuser fouling, and organic spikes can change ozone demand. A 5–15% safety factor helps keep results stable without constantly re-tuning inputs.

6) Is the energy cost estimate accurate?

It is a planning estimate. It multiplies your power (kW) by calculated runtime and your price per kWh. Actual consumption depends on generator efficiency, air preparation, and whether the unit cycles on/off.