A little less guesswork.
Tetra AquaSafe (UK/EU label) calculator
AquaSafe UK/EU label: 5 mL per 10 L of newly added tap water
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 · manufacturer checked 28 October 2026
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How much Tetra AquaSafe do I use?
UK/EU label only
5 mL per 10 L of newly added tap water. Use the water you are adding, not the tank’s advertised capacity.
AquaSafe Plus and bottles with different regional directions need their own reference. Check your bottle before using these examples.
Small-volume examples
Use measured new tap water. These examples use the UK/EU AquaSafe label, without a decor deduction.
Litres
- 5 L2.5 mL
- 10 L5 mL
- 20 L10 mL
US gallons
Unit conversion only—not a US-market bottle’s dose.
- 2 US gal7.5708 L3.79 mL
- 3 US gal11.3562 L5.68 mL
UK gallons
A UK gallon is larger than a US gallon.
- 1 UK gal4.5461 L2.27 mL
Each row is a separate example. Gallon rows use the same UK/EU formula. Displayed decimal places do not guarantee measuring accuracy; check your equipment.
Which volume should I enter?
A 20 L change in a 100 L aquarium
Enter 20 L of new tap water: 20 ÷ 10 × 5 = 10 mL. Entering 100 L would calculate 50 mL for a different amount of new water.
Before adding AquaSafe
- Match the bottle. Confirm the UK/EU formulation and the applicable directions.
- Prepare as instructed. Shake first; Tetra directs marine users to switch off the protein skimmer during application.
- Check other treatments. A conditioner amount does not establish compatibility with medication. Read the combination checks.
Common AquaSafe questions
How much for a one-gallon tank?
First establish which gallon and how much new tap water is being added. One US gallon is about 3.7854 L; one UK gallon is about 4.5461 L. A tank’s nominal capacity is not its measured water or replacement-water amount.
The calculator’s lower limit is 3.8 L, so exactly one US gallon is outside its supported range. Do not round your volume up to bypass it. Follow your exact label and obtain a suitable measuring method for smaller volumes.
How long does AquaSafe take to work?
Tetra describes rapid neutralisation of the listed tap-water substances. Follow your bottle’s application directions; that claim does not establish that a new biofilter is cycled or that fish can be added without assessing water quality.
Is AquaSafe Plus the same reference?
This calculator covers the stated UK/EU AquaSafe label. Do not use its amount for a differently labelled regional product just because the name is similar.
Sources and next steps
Tetra AquaSafe manufacturer directions → · Checked 28 October 2026. Worked examples are editorial arithmetic, not product tests or blanket safety assurances.