Example Data Table
| Stock | Target | Final volume | Concentrate needed | Use-case note |
|---|---|---|---|---|
| 3% | 100 ppm | 1 L | 3.33 mL | Light reservoir dose for routine maintenance |
| 3% | 300 ppm | 1 L | 10.00 mL | Often used for foliar spray testing |
| 12% | 200 ppm | 5 L | 8.33 mL | Higher stock reduces added liquid volume |
| 35% | 60 ppm | 10 L | 1.71 mL | Very strong stock; add carefully, measure precisely |
Formula Used
Dilution C1 × V1 = C2 × V2
- C1 = stock concentration (%).
- C2 = target concentration (%).
- V2 = final solution volume.
- V1 = concentrate volume to add.
ppm conversion Approximate: 1% ≈ 10,000 ppm, so C2(%) = ppm ÷ 10,000.
How to Use This Calculator
- Select an application so you can compare typical ranges.
- Enter the stock concentration printed on your bottle.
- Set the final volume you want to mix.
- Choose ppm or percent, then enter your target strength.
- Press Calculate and measure the listed concentrate volume.
- Add water until you reach the final total volume.
- Start low, test plants, then adjust gradually.
Practical Safety Notes
- Wear eye protection when using strong concentrates.
- Never mix with bleach, vinegar, or strong acids.
- Store tightly closed, away from heat and sunlight.
- Hydroponics: avoid overdosing; monitor roots carefully.
Why Peroxide Works in Garden Water
Hydrogen peroxide breaks down into water and oxygen, so it can raise dissolved oxygen briefly and suppress some microbes. In reservoirs it can reduce biofilm buildup and keep lines clearer. In soil drenches it may temporarily open air space by oxidizing organic residues. Effects are short, so repeat dosing should be cautious and spaced.
Choosing a Target Strength by Task
Target strength depends on purpose, plant stage, and water temperature. Light hydroponic maintenance often uses 20 to 60 ppm, while algae cleanup may use higher short-term doses. Foliar testing commonly starts around 50 to 150 ppm to avoid leaf burn. For drenches, many growers begin near 100 ppm and observe roots. Increase only after a successful trial on a few plants.
Measuring Accurately in Small Batches
Small volumes demand good measuring tools. Use a syringe or graduated cylinder for milliliters, and mix in a clean container before filling sprayers. This calculator converts ppm and percent and applies C1×V1=C2×V2, giving exact concentrate volume and water volume. Label the bottle with date, target, and crop. Rinse equipment after use to protect seals and nozzles. Calibrate syringes occasionally and replace cracked measuring cups.
Managing Plant Sensitivity and Timing
Peroxide can stress tender seedlings and sensitive ornamentals. Apply during cooler parts of the day and avoid bright sun for foliar sprays. In hydroponics, watch for whitening roots or slowed growth, and reduce dose immediately. After dosing, monitor pH and EC; peroxide itself is not a nutrient but can change microbial balance. If you use beneficial microbes, dose peroxide on a different day.
Storage, Compatibility, and Recordkeeping
Store peroxide in its original vented container, tightly closed, away from heat. Use clean measuring tools to avoid contamination that accelerates breakdown. Never combine with bleach, strong acids, or unknown cleaners. Keep a simple log of ppm, frequency, and plant response, then refine your standard recipe for each system. Record water volume units so future batches stay consistent.
Can I use this for household disinfecting recipes?
This calculator is designed for gardening dilutions and volumes. For household disinfection, follow the product label and public health guidance. Concentrations, contact times, and surfaces differ from plant and water applications.
Why does the tool show both ppm and percent?
Growers often think in ppm for reservoirs and in percent for bottle labels. The calculator converts between them using the common approximation that 1% equals about 10,000 ppm, then applies the same dilution equation.
Is higher strength always better for algae?
No. High doses can burn leaves, irritate roots, and disrupt beneficial biology. Start with a low, short-term dose, improve light control and filtration, then increase gradually only if plants respond well.
Can I mix peroxide with nutrients in the same tank?
Many people add peroxide to a filled tank, but it can oxidize some organics and alter microbial products. If you use biological additives, separate dosing days. Always add peroxide slowly with circulation running.
How long does a mixed solution remain effective?
Peroxide decomposes over time, especially with light, heat, or contamination. Mixed solutions are best used the same day. Store briefly in an opaque container and avoid reusing old mixes for sensitive crops.
What measuring method gives the best accuracy?
Use a syringe or small graduated cylinder for milliliters. Kitchen spoons vary by brand, so treat them as estimates. Mix in a clean jug, label the batch, and rinse sprayers after application.