Calculator
Enter your water volume, target ppm, and product strength. The calculator estimates the milliliters of peroxide solution to add for the chosen concentration.
Recent history
No saved calculations yet. Run the calculator to build exportable history.
Example data table
These examples show typical inputs and the calculated dose volume. Always validate plant sensitivity and label guidance before applying peroxide in active grow systems.
| Water volume | Target ppm | Strength | Density used | Estimated dose |
|---|---|---|---|---|
| 10 L | 50 ppm | 3% | 1.01 g/mL | ≈ 16.50 mL |
| 25 L | 80 ppm | 6% | 1.03 g/mL | ≈ 32.36 mL |
| 5 US gal | 100 ppm | 12% | 1.05 g/mL | ≈ 15.03 mL |
| 100 L | 150 ppm | 35% | 1.13 g/mL | ≈ 37.94 mL |
Formula used
How to use this calculator
- Measure your water volume and choose liters or gallons.
- Select a target ppm suited to your gardening purpose.
- Enter your peroxide strength from the product label.
- Keep Auto density, or enter custom density if known.
- Press Calculate to see the dose above the form.
- Download CSV or PDF to save and share results.
Guidance and Reference
Why dosing accuracy matters in garden water
Hydrogen peroxide adds short-lived oxidizing power that can reduce biofilm, algae, and unwanted odors in stored water. In recirculating systems, overdosing can stress roots and beneficial microbes, while underdosing may not meaningfully improve cleanliness. A ppm target expresses the desired milligrams of pure peroxide per liter of water, which makes planning consistent across buckets, tanks, and reservoirs for practical, repeatable daily decisions.
Understanding strength, density, and real volume
Retail products vary from 3% household solutions to stronger horticultural concentrates. Because labels describe strength by percent, the calculator converts your ppm goal into grams of pure peroxide, then scales up to the grams of solution needed. Density matters because stronger solutions are heavier than water; using a realistic g/mL value improves the final milliliter dose, especially for higher strengths.
Typical use cases for growers and maintenance
Reservoir maintenance often uses moderate ppm to limit slime in lines, stones, and filters. Sanitizing tools or containers can use a separate bath with measured doses to avoid wasting concentrate. For irrigation tanks, uniform mixing is critical, so dose should be calculated for full tank volume, not partial fill. Keep notes to compare results across crops and seasons.
Mixing practice and monitoring after application
Add solution slowly with circulation running, then wait before measuring again. Temperature, organic load, and sunlight reduce active peroxide faster, so the same ppm may not persist equally in every situation. If your system already uses inoculants, consider timing peroxide treatments to avoid immediate contact with freshly added microbes. Re-check clarity, odor, and root appearance to guide adjustments.
Recordkeeping, exports, and safer repeatability
Consistent logs turn one-off calculations into a repeatable routine. This tool stores recent runs locally per browser session, then exports them to CSV for spreadsheets or to PDF for on-site reference. Use the safety cap to prevent accidental high targets, and document water volume, strength, and observations. Better records help you troubleshoot, standardize cleaning cycles, and communicate procedures to staff.
FAQs
1) What does ppm mean in this calculator?
ppm is treated as mg of pure hydrogen peroxide per liter of water. The calculator converts that target into the amount of peroxide solution needed at your selected strength.
2) Why does density change the milliliter dose?
Percent strength is treated as a mass fraction. Density converts the required solution mass into a liquid volume. Stronger solutions are denser, so ignoring density can slightly misstate the dose.
3) Can I use gallons instead of liters?
Yes. Select US gallons or UK gallons and enter your volume. The calculator converts your input to liters internally, then reports the final dose in milliliters and other common measures.
4) What if my label lists a different density?
Choose Custom density and enter the value from your product label. This is most useful for stronger concentrates where density varies more between manufacturers.
5) How should I add peroxide to a reservoir?
Add slowly with circulation running, avoid splashing, and let it mix thoroughly. Re-check system response after a short wait, then adjust your next application based on observations.
6) Will the CSV and PDF include my notes?
Yes. Each calculation saves your application and notes in the session history. Exports include the same fields so you can track what was done and compare outcomes later.