A little less guesswork.
API Pimafix calculator
API Pimafix standard aquarium liquid — 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 is the seven-day plan used?
The US Pimafix reference is 5 mL per 10 US gallons daily for seven days, followed by a 25% water change. The result keeps daily amounts separate from aftercare.
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.
Daily for seven days
| Stage | Amount or action for 100 L |
|---|---|
| Day 1 | 13.21 mL |
| Day 2 | 13.21 mL |
| Day 3 | 13.21 mL |
| Day 4 | 13.21 mL |
| Day 5 | 13.21 mL |
| Day 6 | 13.21 mL |
| Day 7 | 13.21 mL |
| After seven days | Make a 25% water change; reassess before any continuation. |
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
Shake well, remove carbon if possible, and follow API’s UV and protein-skimmer instructions. Do not interpret a daily amount as a total course quantity or add all seven at once.
Product-specific checks from the calculation record
- Shake well, remove activated carbon if possible, and stop the protein skimmer and UV during treatment as directed.
- 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.
Should I automatically continue after day seven?
The calculator does not decide that. Review the fish, water quality and applicable manufacturer directions before continuation.
Sources and next steps
Manufacturer page consulted 28 October 2026. Match the exact bottle and leaflet; editorial review does not establish diagnosis or compatibility.