# 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.
- Per-tank-size dose pages (computed with the same engine): https://tankdosing.com/fertilizer-calculator/ (10, 20, 29, 40, 55, 75, 125 US gal).
- Plans: Free (every calculator, tanks saved in the browser, .ics reminders). Plus $2/month or $15/year: tanks synced across devices, dosing log, test-result trend charts, private calendar feed. https://tankdosing.com/pricing/
- 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: Planted Tank Fertilizer & Dry Salt Doses | TankDosing](https://tankdosing.com/): Free planted tank fertilizer calculator for EI, PPS-Pro and low-tech: grams of KNO3, KH2PO4, K2SO4, MgSO4 and CSM+B per dose, stock solution recipes, ppm per element and a weekly schedule.
- [Pricing: Free Dosing Calculators, Plus $2/month or $15/year | TankDosing](https://tankdosing.com/pricing/): Every TankDosing calculator is free with no login. Plus ($2/month or $15/year) adds synced tanks across devices, a dosing log, test-result trend charts and a calendar feed.
- [Privacy Policy | TankDosing](https://tankdosing.com/privacy/): How TankDosing handles data: calculators run in your browser, saved tanks stay on your device, Plus accounts store only what you sync, and Stripe handles payments.
- [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.
- [Fertilizer calculator for a 10 gallon planted tank](https://tankdosing.com/fertilizer-calculator/10-gallon/): Fertilizer doses for a 10 US gallon (38 L) planted tank: EI, lean EI and low-tech grams of KNO3, KH2PO4, K2SO4, MgSO4 and CSM+B, a 500 mL stock recipe, and Seachem and Tropica label doses.
- [Fertilizer calculator for a 125 gallon planted tank](https://tankdosing.com/fertilizer-calculator/125-gallon/): Fertilizer doses for a 125 US gallon (473 L) planted tank: EI, lean EI and low-tech grams of KNO3, KH2PO4, K2SO4, MgSO4 and CSM+B, a 500 mL stock recipe, and Seachem and Tropica label doses.
- [Fertilizer calculator for a 20 gallon planted tank](https://tankdosing.com/fertilizer-calculator/20-gallon/): Fertilizer doses for a 20 US gallon (76 L) planted tank: EI, lean EI and low-tech grams of KNO3, KH2PO4, K2SO4, MgSO4 and CSM+B, a 500 mL stock recipe, and Seachem and Tropica label doses.
- [Fertilizer calculator for a 29 gallon planted tank](https://tankdosing.com/fertilizer-calculator/29-gallon/): Fertilizer doses for a 29 US gallon (110 L) planted tank: EI, lean EI and low-tech grams of KNO3, KH2PO4, K2SO4, MgSO4 and CSM+B, a 500 mL stock recipe, and Seachem and Tropica label doses.
- [Fertilizer calculator for a 40 gallon planted tank](https://tankdosing.com/fertilizer-calculator/40-gallon/): Fertilizer doses for a 40 US gallon (151 L) planted tank: EI, lean EI and low-tech grams of KNO3, KH2PO4, K2SO4, MgSO4 and CSM+B, a 500 mL stock recipe, and Seachem and Tropica label doses.
- [Fertilizer calculator for a 55 gallon planted tank](https://tankdosing.com/fertilizer-calculator/55-gallon/): Fertilizer doses for a 55 US gallon (208 L) planted tank: EI, lean EI and low-tech grams of KNO3, KH2PO4, K2SO4, MgSO4 and CSM+B, a 500 mL stock recipe, and Seachem and Tropica label doses.
- [Fertilizer calculator for a 75 gallon planted tank](https://tankdosing.com/fertilizer-calculator/75-gallon/): Fertilizer doses for a 75 US gallon (284 L) planted tank: EI, lean EI and low-tech grams of KNO3, KH2PO4, K2SO4, MgSO4 and CSM+B, a 500 mL stock recipe, and Seachem and Tropica label doses.
- [Aquarium fertilizer calculator by tank size](https://tankdosing.com/fertilizer-calculator/): Planted aquarium fertilizer doses for 10, 20, 29, 40, 55, 75 and 125 gallon tanks: EI grams of KNO3, KH2PO4, K2SO4 and CSM+B per dose, stock recipes and Seachem Flourish doses.
- [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, sourced guides to planted aquarium fertilizing: EI and PPS-Pro, nitrate, phosphate and potassium levels, stock solutions, Seachem and Tropica dosing, 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.
- [How much potassium does a planted tank need?](https://tankdosing.com/guides/potassium/): Potassium (K) for planted aquariums: typical weekly targets for EI, lean and low-tech tanks, how much K comes from KNO3 and KH2PO4, when to add K2SO4, and grams for your tank.
- [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.
- [Seachem Flourish dosing chart and calculator](https://tankdosing.com/guides/seachem-flourish-dosing/): How much Seachem Flourish, Flourish Nitrogen, Phosphorus, Potassium and Iron to dose for 10 to 125 gallon tanks, from Seachem's own directions, with the ppm each dose adds.
- [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.
- [Tropica fertiliser dosing calculator](https://tankdosing.com/guides/tropica-dosing/): Tropica Specialised and Premium Nutrition dosing by tank size from Tropica's directions (6 mL per 50 L weekly), pumps per week, and the nitrate, potassium and iron each dose adds.
- [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.