Example data table
| Scenario | Final Volume | Target | Purity | Pellets Needed |
|---|---|---|---|---|
| Mild garden tool wash | 5 L | 10 g/L | 98% | 51.02 g |
| General cleaning batch | 10 L | 20 g/L | 97% | 206.19 g |
| Percent-based mix | 3 L | 2% w/w | 99% | 60.61 g |
Saved results
| Time | Mode | Volume (L) | Target | Pellets (g) |
|---|---|---|---|---|
| No saved results yet. Run a calculation to populate this table. | ||||
Formula used
How to use this calculator
- Pick a target style: concentration (g/L) or percent (w/w).
- Enter the final solution volume you want to prepare.
- Enter lye purity from the packaging label.
- Enter your target strength, then click Calculate Dose.
- Follow the mixing guidance: add pellets to water, stir, then top up.
- Use downloads to store your batch history for later reference.
Why dose accuracy matters in garden workflows
Small concentration changes can shift cleaning performance and user safety. A 10 L batch at 20 g/L needs 200 g of pure sodium hydroxide; with 97% purity, pellets rise to about 206 g. This calculator standardizes that adjustment so repeated batches stay consistent.
Understanding strength inputs: g/L versus percent
Use g/L when you follow concentration recipes and want direct mass-per-volume control. Use percent (w/w) when your guidance is expressed as a mass share of the final solution. For percent mode, the tool uses a practical 1 L ≈ 1,000 g approximation for water-like solutions.
Purity and packaging labels
Pellet products often list purity between 95% and 99%. Purity is a multiplier in the dose equation: Pellets Needed = Pure NaOH ÷ (Purity/100). Entering the correct label value can prevent under-dosing that wastes time and over-dosing that increases hazards and material stress.
Mixing process data and temperature awareness
Lye dissolving is strongly exothermic, so temperature impacts handling risk more than the mass calculation. Warmer conditions can accelerate dissolving and increase splash risk. Mix slowly, add lye to water, and allow cooling before transferring or topping up to the final volume.
Recordkeeping, exports, and repeatable batches
Operational consistency improves when you log each run. The saved-results table stores time, target, volume, purity, and pellets needed, then exports to CSV for spreadsheets or PDF for job folders. This supports audits, team handoffs, and reliable preparation across different gardeners and sites.
FAQs
1) Is the water amount exact?
No. The water value is a mixing guide that subtracts pellet mass (as liters) from the final volume. Real solutions can change volume slightly. Always verify the final level after mixing and cooling.
2) Which target method should I choose?
Choose g/L when your recipe specifies grams per liter. Choose percent (w/w) when instructions specify a percentage solution by mass. Both modes adjust for pellet purity automatically.
3) Why does purity change the pellet dose?
Purity indicates how much of the pellet mass is active NaOH. Lower purity means you need more pellets to reach the same active mass. The calculator divides the required pure mass by the purity fraction.
4) Can I save multiple calculations?
Yes. Check “Add to session table” before calculating. Your recent entries appear under Saved results, and downloads will include the saved rows for convenient reporting.
5) What units does the tool use?
Volumes are in liters, doses are in grams, and purity is percent. Percent mode treats 1 liter as roughly 1,000 grams of solution mass for practical planning.
6) What safety basics should I follow?
Use eye protection and chemical-resistant gloves, work in ventilation, and keep clean water available. Always add lye to water slowly, never the reverse. If exposure occurs, rinse with plenty of water and seek medical help.