Why this number
This calculator helps you translate tank volume (and current vs target levels where asked) into a practical nitrogen (N) dose using common Flourish Nitrogen assumptions. It is a dosing aide — not a full Estimative Index spreadsheet.
Planted tanks need balanced macros and micros. Fixing only N while CO₂ or light is chaotic rarely greens plants overnight.
How to use it
- Enter accurate water volume (décor reduces usable liters).
- Follow on-screen fields for current/target concentrations when present.
- Dose into high-flow areas; avoid dumping concentrate on sensitive shrimp.
- Retest after a few days — chase trends, not a single reading.
Limits
- Brand bottle instructions still win if they conflict with a generic chart.
- EI/PPS systems use scheduled macros; this page is element-focused.
- Yellow new leaves may be iron-related; old-leaf yellow often nitrogen — see yellow leaves troubleshoot.
Related dose tools
FAQ
Is this a full EI calculator?
Not yet — it focuses on N. Use it with a consistent weekly schedule and test kit.
Can I dose every day?
Only if your method calls for it (some lean daily micro routines). Beginners usually do better with fewer, measured doses.
Will more N stop algae?
Not by itself. Balance light, CO₂, and cleanup first.
Safe for shrimp?
Dose carefully and avoid copper-heavy products in shrimp tanks. When unsure, half-dose and observe.
What if plants still yellow?
Map old vs new leaves and check CO₂/light before stacking bottles.
Field notes from our tanks
We treat calculator output as a starting hypothesis. After you change light, CO₂, or stocking, give the tank several days and retest before stacking another change. Most algae and melt episodes come from two changes at once, not from a single “wrong” number on day one.
Keep a small notebook (or phone note) with tank dimensions, KH, photoperiod, and the date you changed livestock. That record makes the next calculator run faster and keeps Budget Setup / Troubleshoot links honest for your exact system.