A little less guesswork.
Seachem Flourish Excel calculator
Flourish Excel liquid — select initial or ongoing use
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
Jump to a section
Initial addition or ongoing amount?
Initial use and a water change greater than 40% use a different reference from ongoing daily/every-other-day additions. Choose the correct stage and enter aquarium water volume.
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.
Initial use / after a water change greater than 40%
| Stage | Amount or action for 100 L |
|---|---|
| Initial / major-water-change dose | 12.5 mL |
Ongoing addition — daily or every other day
| Stage | Amount or action for 100 L |
|---|---|
| Daily or every other day | 2.5 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
Visual help: Read your bottle label · Read a small liquid scale. Teaching diagrams do not replace your bottle or measuring-device instructions.
Excel supplies organic carbon; it is not dissolved CO₂. Seachem warns that overdosed spot applications can damage plants. This calculator supplies no spot-treatment recipe.
Product-specific checks from the calculation record
- The initial and ongoing amounts are alternatives for the selected stage, not two additions to combine.
- Anacharis is sensitive; Seachem advises every-other-day use for that plant. Follow the product instructions rather than an unsupported spot-treatment recipe.
Does every water change need the initial amount?
The manufacturer’s initial-use reference also applies after a major water change greater than 40%. Do not select it automatically for every small change.
Sources and next steps
Seachem manufacturer directions →
Manufacturer page consulted 28 October 2026. Match the exact bottle and leaflet; editorial review does not establish diagnosis or compatibility.
Optional buying links
Find this product
Affiliate links. As an Amazon Associate I earn from qualifying purchases.
Seachem Flourish Excel, 500 mL
View on Amazon US (affiliate link) — Seachem Flourish Excel, 500 mL; opens in a new tabCheck the selected bottle, formulation and label before buying. These links do not select a treatment or change your dose. Prices, sellers and availability are shown on Amazon. About these links.