NPK Calculator Online for Hydroponics

What's Inside

4 tools in one app

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Dose Calculator

Select a crop, growth phase, and tank volume — get instant fertilizer concentrate dosages.

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Seeding Rates

70 microgreen crops: seeding rates per berry tray. Search and filters.

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Diagnostics

25+ common growing problems: yellowing, spots, curling — with cause and precise solution.

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Concentrate Recipe

Clear instructions for preparing stock solutions, proportions for your volume, and the correct mixing order.

How It Works

Three steps from start to ready solution

Select crop and growth phase

Enter working solution volume

Measure and mix in the correct order

A → B → C. Add each component with 30-second stirring. Check EC and pH — nutrient profile is ready.

Crop Nutritional Profiles

Different formula compositions for different crops

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New crops and features are added based on grower requests.

Fertilizers — Concentrate Composition

Six components forming the nutritional profile

Concentrate A

6-14-30

Yara Ferticare Hydro

Main NPK complex with micronutrients. Balanced nitrogen, phosphorus and potassium for active growth.

Concentrate B

13.5-0-46

Leda Potanit

Potassium nitrate. Potassium and nitrogen without chlorine — improves product quality and density.

Concentrate B

11-0-0 +16MgO

Leda Maganit

Magnesium nitrate. Magnesium in readily available form — the basis of chlorophyll and enzymes.

Concentrate C

15.5N · 26.5Ca

YaraTera Calcinit

Calcium nitrate. Strengthens cell walls, prevents blossom-end rot and tip burn.

Concentrate C

Fe 10% EDDHA

Brexil Fe

Iron chelate. Absorbed at any pH — eliminates chlorosis and yellowing of young leaves.

Concentrate D

0-52-34

YaraTera MKP

Monopotassium phosphate. Phosphorus and potassium without nitrogen — stimulates roots and flowering.

Concentrate Preparation Instructions

Mixing order — the key to a clean solution without precipitate

Profile 1 — order in working tank

A→ B→ C

A — Ferticare Hydro
B — Potanit + Maganit
C — Calcinit + Brexil Fe

Profile 2 — order in working tank

A→ B→ D→ C

D — MKP — before C!
C always last — Ca²⁺ and PO₄³⁻
must not meet in concentrated form

⚠️ C (Calcinit) and B (Potanit) — never mix directly in concentrated form. Only alternately in a large tank with water. Each tank — a separate measuring cup without rinsing.

Nutritional Profile Recipe

Solution composition: mg/L (ppm) · EC in mS/cm

Profile 1 — Greens & Microgreens

🌱 Microgreens EC 0.64–1.29 mS/cm

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Phase	N	P	K	Ca	Mg	S	Fe	EC	Norm
Start	59	12	88	34	10	7	0.8	0.64	0.5–0.8
Vegetation	121	25	186	68	21	16	1.7	1.29	1.0–1.6

🥬 Lettuce EC 1.01–1.61 mS/cm

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Phase	N	P	K	Ca	Mg	S	Fe	EC	Norm
Start	93	20	150	49	17	13	1.3	1.01	0.8–1.2
Vegetation	152	31	230	87	26	19	2.2	1.61	1.2–2.0

🌿 Basil EC 1.23–1.92 mS/cm

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Phase	N	P	K	Ca	Mg	S	Fe	EC	Norm
Start	115	24	177	65	20	15	1.7	1.23	1.0–1.4
Vegetation	184	37	274	106	31	23	2.6	1.92	1.6–2.2

🌾 Herbs EC 1.01–1.61 mS/cm

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Phase	N	P	K	Ca	Mg	S	Fe	EC	Norm
Start	93	20	150	49	17	13	1.3	1.01	0.8–1.2
Vegetation	152	31	230	87	26	19	2.2	1.61	1.4–1.8

🍃 Mint EC 1.23–1.80 mS/cm

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Phase	N	P	K	Ca	Mg	S	Fe	EC	Norm
Start	115	24	177	65	20	15	1.7	1.23	1.0–1.4
Vegetation	172	36	254	103	29	22	2.5	1.80	1.6–2.0

🥗 Chard EC 1.01–1.60 mS/cm

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Phase	N	P	K	Ca	Mg	S	Fe	EC	Norm
Start	93	20	150	49	17	13	1.3	1.01	0.8–1.2
Vegetation	152	31	222	91	25	19	2.2	1.60	1.4–1.8

Profile 2 — Fruiting crops, berries, flowers

🍅 Tomato EC 1.24–2.40 mS/cm

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Phase	N	P	K	Ca	Mg	S	Fe	EC	Norm
Start	120	27	151	81	20	13	1.5	1.24	1.0–1.5
Vegetation	219	59	281	152	36	24	2.9	2.25	2.0–2.5
Flowering	264	88	375	171	47	27	3.2	2.74	2.5–3.0
Fruiting	286	110	424	185	50	29	3.5	3.00	2.5–3.5
Ripening	228	83	348	133	44	21	2.5	2.40	2.0–2.8