# TankDosing

> Planted tank fertilizer dosing calculator. Free, no login. Computes grams (dry dosing) or bottle recipes (stock solutions) of KNO3, KH2PO4, K2SO4, MgSO4·7H2O and CSM+B for a target ppm, plus label doses and ppm for Seachem Flourish and Tropica liquids.

Key facts:
- Element fractions come from IUPAC atomic weights: KNO3 is 61.33 % NO3 and 38.67 % K; KH2PO4 is 69.79 % PO4; K2SO4 is 44.88 % K; MgSO4·7H2O is 9.86 % Mg.
- ppm = grams × 1000 × fraction ÷ liters. Example: 1 g KNO3 in 100 L adds 6.13 ppm NO3.
- Steady state: with weekly dose D and weekly water change fraction f, levels settle near D ÷ f before each change.
- Method presets (weekly ppm, educational starting points): Estimative Index (EI): NO3 22.5, PO4 3, K 30, Mg 6, Fe 0.6; Lean EI: NO3 12, PO4 1.5, K 15, Mg 3, Fe 0.3; PPS-Pro style (daily): NO3 7, PO4 0.7, K 9.3, Mg 0.7, Fe 0.1; Estimative-style low-tech (weekly): NO3 5, PO4 0.5, K 5, Mg 1, Fe 0.1.
- CSM+B analysis used (Fe 6.53 %) is a typical published label value and an assumption; check your bag.
- Liquid product data comes only from the makers' pages; where a label gives % by weight we assume 1.0 g/mL.
- Prefill the calculator by URL: https://tankdosing.com/?v=40&u=usgal&m=ei&wc=50&mode=dry (keys: v volume, u L|usgal|ukgal, net % net water, m ei|lean|pps|low|custom, no3 po4 k mg fe weekly ppm, d macro doses/week, mi micro doses/week, wc water change %, mode dry|stock, bottle mL, dml mL per dose).

## Pages
- [EI Dosing Calculator for Planted Tanks: Dry Salts & Stock Solutions | TankDosing](https://tankdosing.com/): Free planted aquarium fertilizer calculator. Grams of KNO3, KH2PO4, K2SO4, MgSO4 and CSM+B per dose, 500 mL stock solution recipes, ppm per element and a weekly dosing schedule.
- [Pricing: Free Dosing Calculators, Plus Coming Soon | TankDosing](https://tankdosing.com/pricing/): Every TankDosing calculator is free with no login. Plus ($2/month or $15/year, coming soon) adds synced tanks, reminders, a dosing log and test-result tracking.
- [Privacy Policy | TankDosing](https://tankdosing.com/privacy/): How TankDosing handles data: calculators run in your browser, saved tanks stay on your device, and waitlist emails are used only to announce Plus.
- [Seachem Flourish & Tropica Dosing Calculator: mL and ppm for Your Tank | TankDosing](https://tankdosing.com/products/): Label doses for Seachem Flourish, Flourish Nitrogen, Phosphorus, Potassium, Iron and Tropica Premium and Specialised Nutrition, scaled to your tank, with the ppm each dose adds and mixed plans.
- [My Tanks: Saved Dosing Plans, Calendar Reminders and Printable Charts | TankDosing](https://tankdosing.com/tanks/): Your saved planted tanks and dosing plans, stored privately in this browser. Download calendar reminders (.ics) or print a weekly dosing chart.
- [Terms of Use and Safety Disclaimer | TankDosing](https://tankdosing.com/terms/): Terms for using TankDosing: estimates for education only, check units and labels, and you are responsible for your livestock.
- [Dry vs liquid fertilizers: which should you use?](https://tankdosing.com/guides/dry-vs-liquid/): Dry fertilizer salts versus commercial liquid fertilizers: cost, accuracy, convenience, and how to compare Seachem or Tropica doses with EI dry dosing.
- [What is EI dosing?](https://tankdosing.com/guides/ei-dosing/): EI (Estimative Index) dosing explained: how it works, typical weekly nitrate, phosphate and potassium numbers, why the 50% water change matters, and how to work out your doses.
- [Planted Tank Fertilizer Guides: EI, Stock Solutions, Deficiencies | TankDosing](https://tankdosing.com/guides/): Plain-English guides to planted aquarium fertilizing: EI and PPS-Pro dosing, nitrate and phosphate levels, stock solutions, water changes, K2SO4, MgSO4 and deficiency signs.
- [K₂SO₄ and MgSO₄ explained](https://tankdosing.com/guides/k2so4-mgso4/): Potassium sulfate (K2SO4) and magnesium sulfate (Epsom salt) in planted tank dosing: what they add, when you can skip them, and where MgSO4 goes.
- [Beginner low-tech planted tank dosing](https://tankdosing.com/guides/low-tech-dosing/): A simple fertilizer plan for low-tech planted tanks without CO2: how much to dose, once a week, root tabs vs liquids, and avoiding algae.
- [How much nitrate and phosphate does a planted tank need?](https://tankdosing.com/guides/nitrate-phosphate-levels/): Practical nitrate (NO3) and phosphate (PO4) ranges for high-tech and low-tech planted aquariums, the N:P ratio, and how to turn a target ppm into grams.
- [Signs of nutrient deficiency in aquarium plants](https://tankdosing.com/guides/nutrient-deficiency/): How to recognize nitrogen, phosphorus, potassium, iron and magnesium deficiencies in aquarium plants, where symptoms appear first, and what to adjust.
- [PPS-Pro dosing explained](https://tankdosing.com/guides/pps-pro/): What PPS-Pro (Perpetual Preservation System) is, how its daily doses compare with EI, its 500 mL recipe, and why it uses conductivity to time water changes.
- [How to make a fertilizer stock solution](https://tankdosing.com/guides/stock-solution/): Step by step: turn a dry fertilizer kit (KNO3, KH2PO4, K2SO4, MgSO4, CSM+B) into 500 mL macro and micro stock solutions, with solubility limits and dosing in mL.
- [How water changes affect fertilizer dosing](https://tankdosing.com/guides/water-changes/): Why the water-change percentage controls where your nutrient levels settle, how to scale doses when you change less water, and the simple steady-state formula.

## Safety
Estimates only. Wrong units or overdosing can harm fish and shrimp; copper is toxic to shrimp at low levels.