A little less guesswork.
API Leaf Zone calculator
API Leaf Zone liquid — freshwater label — US label directions
Read the product guide and worked examples ↓
Clear amounts. Visible assumptions.
Your calculation, explained
Choose a product and enter the water you’re actually dosing.
- Check the exact product and formulation.
- Use measured water, or make an explicit estimate.
- Review the amount, source and any schedule.
Product guide · edited 28 October 2026
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How often is Leaf Zone added?
The API US reference is 5 mL per 10 US gallons weekly for freshwater aquariums with fish and plants. Enter aquarium water volume, not only the volume changed that week.
Worked examples
These illustrations use 100 L of measured water, without a decor deduction. Choose the matching stage or formulation above for your own water volume. They do not select a treatment or establish livestock suitability.
Weekly
| Stage | Amount or action for 100 L |
|---|---|
| Weekly | 13.21 mL |
Example only. Your calculation above uses your own inputs. Small amounts and powder fractions still need equipment that can measure them reliably.
Before you measure
This is the liquid Leaf Zone product, not Root Tabs. A weekly result is not a daily dose. Check the bottle’s regional reference before measuring.
Product-specific checks from the calculation record
- For freshwater plants. This is Leaf Zone, not a different API plant product.
- These quantities follow the manufacturer’s US label. If your bottle gives different reference volumes or strengths, use that label and request its specific variant.
Does this calculator choose a fertiliser programme?
No. It scales Leaf Zone’s stated reference. Record other nutrient additions before changing several parts of the routine.
Sources and next steps
Manufacturer page consulted 28 October 2026. Match the exact bottle and leaflet; editorial review does not establish diagnosis or compatibility.