Boost does not replace the profile, but modifies the current one:
P-boost — sets P=40 ppm to stimulate flowering. Maximum 3-5 days! High P blocks Ca/Mg/Fe.
K-boost — increases K by +20% for fruit ripening. Maximum 5-7 days.
Ca-boost — increases Ca by +20% for blossom end rot prevention.
After boost, return to the base profile!
Profile
0 entries
Journal is empty. Add your first entry!
Solution
mS/cmSalt prices
mS/cm
bar
Last update
π (bar) ≈ 0.36 × EC. For the root to absorb water its internal pressure must be higher than the solution pressure outside. At too high an EC water stops entering — the plant wilts even when watered. In hot weather this is doubly critical.
EC
π (bar)
Crop
Status
0.5–1.0
0.2–0.4
Seedlings, strawberry
↓ Low
1.5–2.0
0.5–0.7
Greens, cucumber
✓ Normal
2.0–2.5
0.7–0.9
Tomatoes, cucumbers, peppers
✓ Normal
2.5–3.5
0.9–1.3
Flowers and ornamentals
○ Acceptable
3.5–5.0
1.3–1.8
Rose, tomato stress
⚠ Stress
5.0–7.0
1.8–2.5
All micro salts
⚠⚠ Universal starter
>8.0
>2.9
Any
✗ Critical
💡 In hot weather a plant transpires more water — the same EC creates more stress.
ECion — calculated EC by ions
Computed from the ionic concentrations (NO₃⁻, H₂PO₄⁻, SO₄²⁻, NH₄⁺, K⁺, Ca²⁺, Mg²⁺, Fe²⁺, Cl⁻) using the Debye–Hückel method — accounting for the activity of ions in solution.
This is NOT a per-liter concentration but the physical EC of the solution by its element composition. When you change the EC field, the grams scale while the target elements stay → ECion doesn't change.
💡 If ECion ≈ EC — the recipe is consistent. If they diverge a lot — check the composition.
pHcalc — private
pH estimate from the NH₄/NO₃ ratio and acid additions. Formula: pH = 6.5 − 2.0 × (NH₄/N) − 0.4 × acid (meq/l).
Accuracy ±0.3–0.5 pH. Depends on the buffering of the water and substrate. Use only as a guide — always measure with a pH meter!
💡 Pure NO₃ → pH ~6.5. Adding NH₄ lowers pH. HNO₃/H₂SO₄/H₃PO₄ also lower it.
Macro0 ₽
Micro:0 ₽
Total:0 ₽
Diagnostics
1.0-2.5
0.8-2.0
3.0-7.0
2.0-4.0
5-251 к 14
Ion activity
Ca²⁺γ=--ppm
Mg²⁺γ=--ppm
Ion activity
The root absorbs not the amount of an ion in solution but its activity — the real «available» fraction. In a saturated solution ions interfere with each other and their activity is lower than the concentration. The γ coefficient (Debye–Hückel) shows this correction: at EC=1.5 γ≈0.45 for Ca²⁺, at EC=3.0 γ≈0.35.
Element
Optimum
Min.
Critical
Ca²⁺ act.
80–120 ppm
60 ppm
<40 ppm
Mg²⁺ act.
20–40 ppm
15 ppm
<12 ppm
💡 Even at the «correct» Ca/Mg ppm a plant may experience a deficiency — if the EC is too high, activity drops.
These are recommendations, not rules. A red indicator is a reason to pay attention, but an experienced agronomist may knowingly go beyond the limits.
Matrix
N
P
K
Ca
Mg
S
N
1
-
-
-
-
P
-
1
-
-
-
-
K
-
1
-
Ca
-
-
1
-
Mg
-
-
1
-
S
-
-
-
-
-
1
Water / Acids
CaCaO0ppm
MgMgO0ppm
SSO₃0ppm
FeFe₂O₃0ppm
KK₂O0ppm
PP₂O₅0ppm
HNO₃
%
g
ml
0 ppm N
H₃PO₄
%
g
ml
0 ppm P
H₂SO₄
%
g
ml
0 ppm S
Macroelements
+ 0 meq- 0 meq
N:
NO3NH4PKCaMgSCl
Salts
Salt
All
Composition %
Container
g/L
ml
g
g/ml
RUB/g
Price
Ca(NO₃)₂·4H₂O
Ca
NO₃
NH₄
KNO₃
K
NO₃
NH₄
NO₃
MgSO₄·7H₂O
Mg
S
KH₂PO₄
K
P
K
S
Mg
NO₃
Ca
Cl
🧪 Не хотите смешивать соли сами?
Закажите готовые концентраты А и Б под текущий профиль — от 100 л рабочего раствора.
Main principle: everything is calculated per 1 liter
The salt table shows grams per 1 liter of the ready solution (the «g/l» column). To prepare a tank or concentrate, use the «Concentrates» section: it multiplies g/l by the required volume and gives the final grams.
Profile selection — click the «Profiles» button (⚡) and choose a ready-made profile: Hydro, Coco, Rockwool, Boost, Classic, Crops or Community (recipes from other growers)
Solution replacement — enter the desired EC; the salt table shows grams per 1 liter of the ready solution
Enter search text — in the «Salts» table choose a brand from the dropdown or enter the percentages manually
My concentrate — scroll to the «Concentrates» section, set the A/B volume (a single field for concentrates A and B) and separately C (the micro concentrate)
Weigh the salt — the «g/l» column is the per-liter amount; the «Concentrates» section gives the final grams for your whole volume
Reset to original value
Click the 🎓 button on the toolbar — an interactive tour of all the calculator's features will start.
Nutrient Element Compatibility
The ratios show the balance between elements. These are RECOMMENDED ranges that depend on:
Coco coir has a cation-exchange capacity (CEC). It «takes» Ca, Mg, K from the solution. That's why in a coco profile Ca and Mg are 20-30% higher than for hydroponics.
Rockwool features
Rockwool is an inert substrate with a very low CEC. New rockwool has a high pH (7-8) and needs flushing with a pH 5.5 solution. It can accumulate salts with poor drainage — monitor the drainage EC. The profile is close to hydroponics, but with slightly higher Ca to buffer the high pH of new wool.
Light type
expanded clay — inert, large fraction, excellent drainage. Profile like for hydroponics.
Perlite — inert, light, good drainage. Often mixed with other substrates.
Vermiculite — retains water and has CEC. Add 10-15% Ca/Mg as for coco.
Peat — has CEC and acidic pH. Requires liming and increased Ca/Mg.
Hydroponics — pure hydroponics, standard profile.
Table
For each salt you can enter the percentage composition manually or pick from a list of ready brands (Fertika, Yara, Master, etc.).
Grams per liter (g/L)
The «g/l» column shows how many grams of salt are needed per 1 liter of the ready solution. This is the base unit of all calculations.
Go to Shop
The «Concentrates» section (at the bottom of the page) takes the grams from g/l and multiplies by the container volume. Set 10 l — get grams for 10 l. Set 100 l — get grams for 100 l. The salt table itself is always in g/l.
Units mg/g — auto-switch
Small amounts (< 1 g/l) are shown automatically in milligrams (mg) to avoid weighing errors:
0.500 g/L → shown as «500 mg»
When entering in mg mode, spinner arrows step by 1 mg
When crossing 1 g — it automatically switches back to g (1.00 g)
Enter percentages from the package
Packages list N, CaO, K₂O, MgO. The calculator needs Ca, NO₃, NH₄, etc. Click «?» in the header of the «%» column — there are detailed conversion formulas there.
Element Compatibility
Ca = CaO ÷ 1.4 | K = K₂O ÷ 1.2 | Mg = MgO ÷ 1.66
N = NO₃ + NH₄
Solution
When you enter g/l in a salt field, a hint with the maximum solubility at 20°C appears. If the value is low, a ⚠️ warning appears next to it.
K:Ca Ratio
Calculated automatically from the entered element values. Color coding:
■ Green — within range for the selected substrate
■ Yellow — acceptable deviation
■ Red — outside the recommended range
Parameters panel (sticky)
As you scroll down, the parameter row (EC, PPM, ECion, pHcalc, π) automatically pins to the top of the screen.
PPM is the total concentration of macronutrients in mg/l, calculated automatically from the entered values.
Last update
π ≈ 0.36 × EC. Shows the physical pressure of the solution — the higher it is, the harder it is for the root to absorb water. Click ⓘ next to «P» — a table of norms for different crops opens.
EC
π (bar)
Crop
Status
0.5–1.0
0.2–0.4
Seedlings, strawberry
↓ Low
1.5–2.0
0.5–0.7
Greens, cucumber
✓ Normal
2.0–2.5
0.7–0.9
Tomatoes, cucumbers, peppers
✓ Normal
2.5–3.5
0.9–1.3
Flowers and ornamentals
○ Acceptable
3.5–5.0
1.3–1.8
Rose, tomato stress
⚠ Stress
5.0–7.0
1.8–2.5
All micro salts
⚠⚠ Universal starter
>8.0
>2.9
Any
✗ Critical
ECion
Calculated EC from the ionic composition (Debye–Hückel method). If ECion ≈ EC — the recipe is consistent. A large discrepancy means the composition doesn't balance at the set EC.
pHcalc
Estimated solution pH by the formula: pH = 6.5 − 2.0 × (NH₄/N) − 0.4 × acid. Accuracy ±0.3–0.5 pH. For guidance only — always verify with a pH meter!
The save (diskette) button is visible both in the sticky panel while scrolling and in the normal position. When clicked, it saves the profile to the server.
Concentrates (g/L)
⚠️ Why not complex?
Ca²⁺ (concentrate A) and SO₄²⁻/PO₄³⁻ (concentrate B) form an insoluble precipitate when mixed in concentrated form. In the working solution (1:100+ dilution) they are compatible.
Reset Grafana user
In the section header set two fields: «A/B» — a single volume for concentrates A and B; «C» — the micro concentrate volume (100 l and 1000 l by default)
Calculator will show final grams of each salt for the specified volume
If you use liquid micro — enter the bottle volume and g/l → get ml
The «Concentrates» section header has a «Maximum» button — it calculates the maximum possible concentrate: how many grams of salt can be dissolved into the container up to the solubility limit. Useful for optimizing storage.
Flowers and ornamentals
Warm water (30C for A/B, up to 100C for mono) - salts dissolve faster
Dissolve one salt at a time, rinse container between components
Label bottles (A/B, date, density), store in dark at +5...+25C
PPE: gloves, goggles; do not inhale salt dust
To check: weigh 100ml of finished solution. Density = mass/100
Water and acids
The «Water / Acids» section accounts for the mineral composition of tap water and the addition of acids to lower pH. The calculator automatically subtracts the water elements from the profile's target values.
«Water» tab
Enter the element content of your water (Ca, Mg, K, S, Na, Cl, HCO₃, etc.). The data comes from a water analysis — usually given in mg/l or ppm. You can enter either % (the oxides column) or ppm.
How to read the table
Hard water contains Ca and Mg — without accounting for it you'll get an excess of these elements in the solution. High HCO₃ (carbonate hardness) buffers pH and requires neutralization with acid.
Water / Acids
To lower the solution pH, one of the acids can be added:
Acids
Effect
Humidity
HNO₃
↓ pH
Adds N — account for in balance
H₃PO₄
↓ pH
Adds P — account for in balance
H₂SO₄
↓ pH, ↓ HCO₃
Adds S, neutralizes carbonates
Adding acid affects ECion and PHcalc
When you add acid, the calculated EC and pH are recomputed — see the sticky panel.
Microelements
The «Micro» section lets you set micronutrient doses: Fe, Mn, Zn, Cu, Mo, B, Co, Si. By default values are shown in ppb (µg/l). Use the button next to the «Micronutrients» heading to switch units: ppb → ppm → µmol.
Total microelements:
In the table: mg/l (= ppm). In ppb mode (default) multiply by 1000 — e.g. Fe 1–3 mg/l = 1000–3000 ppb.
Element
Normal
Role
Fe
1.0–3.0
Chlorophyll, respiration
Mn
0.5–1.0
Tools
Zn
0.1–0.5
Vapor Pressure Deficit
Cu
0.05–0.15
Additional options
Mo
0.05–0.1
My concentrate
B
0.2–0.5
Last update
Co
0.01–0.05
Nitrogen fixation, vitamin B12 in plants
Si
50–150
Cell wall strengthening
Total microelements:
Fe and Mn compete — an excess of one blocks the other. Excess Cu suppresses Fe and Mn. High P blocks Zn and Fe. Click the «Compatibility» button (🛡) on the toolbar for the full table.
Three modes of micro calculation
Salts (chelates) — each element is set by a separate salt: Fe-EDTA 13%, MnSO₄, H₃BO₃, etc. The table shows the salt type, % content, weight/l. The «Composition» row shows the % of each element in the dry fertilizer mix (as on a label).
Complex — one ready-made micro product (bottle): enter the grams and the % of each element in it. Calculated for the concentrate volume.
Salts + Complex — combined mode: part of the micro is from individual salts, part from a ready complex. The «Composition» row shows three lines: «Salts», «Complex» and «Total».
Dry mono micro («Salts» mode)
For each element choose a salt type from the dropdown (Fe-EDTA, Fe-DTPA, MnSO₄, H₃BO₃, etc.) and, if needed, adjust the element's % content. The calculator will compute the salt grams per liter of working solution.
Liquid micro («Complex» mode)
Enter the total grams of the product per liter and the % content of each element in it. The «Concentrate C» section under «Concentrates» will show how many grams or ml are needed for your volume.
Tools
Solution corrector
The «Corrector» section is below the concentrates. It lets you adjust an already-prepared solution without draining it:
Enter the current solution composition (the «Current» column) or click ↓ next to the «Current» header — it fills from the profile
Enter the desired composition (the «Target» column), or click ↓ next to the «Target» header — it fills from the profile
The calculator will show in the «Corr.» column how much to add (+ add / − excess)
Each column has an ↑ «Apply to profile» button: ↑ at «Corr.» — apply the corrected result as a new profile; ↑ at «Current» or «Target» — apply that column's values directly
-- not selected --
The «Mixer» section appears if you have an IoT device connected (ESP32 with pumps). It lets you:
Select mix volume and set precision
Assign a pump (p1–p8) to each salt via the «Pumps» button
Preparing concentrate
Track status and progress in real time
Journal
The journal is available in the profile settings (the ⚙ button on the toolbar — the sliders icon). It lets you keep a history of batches:
Record pH, EC, temperature with timestamp
Preparing concentrate
Profile snapshot at recording time («+ profile» checkbox)
Filter by event type and device
Publish to community recipe database
Exchange string
The «Exchange string» is in the NPK block above the salt table. It shows the full ionic composition in a single line — macro and micro ppm: NO3= NH4= P= K= Ca= Mg= S= Fe= Mn= B=... ppm. The 📋 button next to it copies it to the clipboard. Handy for forum discussions and comparing recipes.
Open for all
The 🖨️ button on the toolbar generates a printable version of the profile: the salt table, grams, concentrates and the preparation steps on one sheet.
Element Compatibility
The 🛡 button on the toolbar — a table of antagonisms and synergies. Useful with micro deficiencies: high P blocks Zn and Fe, excess K interferes with Ca and Mg.
Community Recipes
The profiles modal (⚡) has a «Community» tab — ready recipes from other growers with photos and descriptions. Click «Apply» — the profile loads into the calculator.
Reset profile
↺ button on the toolbar opens reset menu with five options:
Load last save from server — Load last save from server
PPM of elements — default — reset the target values of N, P, K, Ca, Mg, S, Fe, etc. to the standard profile (N=150, P=50, K=200, Ca=180, Mg=50…)
Total salts: — reset the salt and micro percentages to the standard values (by pure compounds)
Reset — restore PPM to standard profile and standard % simultaneously
Load from journal — rollback profile to any journal entry that has a snapshot
Calibrate pH and EC meters. If necessary - water treatment
Specify salt composition (% elements from package). Example: CaO~27%, N~14.9%, NH4~0.2%
Calculate profile: target macro/micro and ratios (K:N, K:Ca, K:Mg)
Prepare concentrates A, B and Micro for the given volumePrepare concentrates A, B and Micro for the specified volumePrepare concentrates: macro for 100L, micro for 100L (or from dry salts)
Measure with scales (g) or syringe (ml). Use density for ml to g conversion
Assemble A and B: Ca separate from phosphates/sulfates, dissolve one at a time
pH can be adjusted by NH4:NO3 ratio (more NH4 = more acidic)
Monitor EC, dilute with pure water if necessary
Don't discard solution - use Corrector to adjust
Keep a journal: save profile, photos and comments
Tips
Hard water - use RO or reduce alkalinity with acid
Watch the osmotic pressure in the panel — at high EC in hot weather the stress is doubled
ECion ≠ EC? Review the salt % — there may be a mismatch with the real composition
Weigh small salt doses (mg) on jewelry scales (0.01 g accuracy)
they go through a moderation process.
How to read the table
Packages list N (total nitrogen) and CaO (calcium oxide), while the calculator uses Ca, NO₃ and NH₄ separately.
Adjust Ca, NO₃, NH₄ to match the package:
Conversion formulas
N = NO₃ + NH₄
CaO = Ca × 1.4 (or Ca = CaO ÷ 1.4)
Potassium nitrate
On the package: N 17%, CaO 32%
Loading calculator...
Ca: 32 ÷ 1.4 = 22.9% → Shopping Cart CaO = 32%
NO₃: 16.8%
NH₄: 0.2%
Shopping Cart N = 17% ✓
All conversion factors
Element
Oxide
Copy
Ca
CaO
× 1.40
K
K₂O
× 1.20
Mg
MgO
× 1.66
P
P₂O₅
× 2.29
S
SO₃
× 2.50
Effect of crystallization water
Preservative for microelements
Form
Ca
N
Ca(NO₃)₂ anhydrous
24.4%
17.1%
Ca(NO₃)₂·H₂O
22.0%
15.4%
Ca(NO₃)₂·4H₂O
17.0%
11.9%
Element Compatibility
Macro
NH₄→P⊗Ca,Mg
NO₃→Ca,Mg
P→K⊗Zn,Fe
K⊗Ca,Mg
Ca→NO₃⊗K,Mg
Mg⊗K
S⊗Mo
Micro
Fe→Mn⊗Zn,Cu
Zn⊗Fe
Cu→Fe⊗Mn
Mn→Fe⊗Cu
Mo⊗S
B→Ca
→ helps absorption
⊗ blocks
Edit fertilizer
⚠️ Why not complex?
Ca²⁺ from concentrate A and SO₄²⁻/PO₄³⁻ from concentrate B form an insoluble precipitate when mixed in concentrated form. In the working solution (1:100+ dilution) they coexist safely.
А
Concentrate A
Ca(NO₃)₂, KNO₃, NH₄NO₃, Mg(NO₃)₂, CaCl₂
Weigh all salts A according to calculation
Mark the level — fill water to the A/B container volume (usually 100 l) and make a mark
Pour into container
Top up to volume, stir. Calculate density (mass/volume)
Fill with water and bring to mark
💡 Ca(NO₃)₂ dissolves well even in cold water. NH₄NO₃ — in hot.
Б
Concentrates (g/L)
MgSO₄, KH₂PO₄, K₂SO₄
Weigh salts B according to calculation
Dissolve in a separate container — not in container A!Dissolve in a separate container — not in container A!
MgSO₄·7H₂O dissolves well in hot water (~50°C)
KH₂PO₄ dissolves slower — mix thoroughly
Bring to 1 liter
⚠️ Never mix A and B in concentrated form — precipitation will occur!
В
Preservative for microelements
Fe, Mn, Zn, Cu, Mo, B, Co, Si
Weigh micro-salts or measure complex chelate according to calculation
Dissolve in a separate container C — the volume is shown in the calculator (usually 1000 l)
For chelates (EDTA) — use water 20–40°C, not boiling
Bring to 1 liter
💡 A chelated complex (Plantafol, Master, etc.) can be dissolved separately and added to tank C.
Preparing concentrate
Weigh the salts → mark the container volume level → pour out the water → add the salts
Fill with water and bring to mark
To check: weigh 100ml of finished solution. Density = mass/100
Weigh the salt How to work with calculator
Weigh the salt Fill with water and bring to mark
Pour out the water Pour into container
Pour hot water (~60-80°C) to 2/3 of the volume
until completely dissolved Pour hot water
Bring to 1 liter until completely dissolved
Open for all
Calculate Solution
ProfileOHPG
EC:- mS/cm | g/vol- L
OHPG - Nutrient Solution Calculator
1 Tutorial Videos
Order matters: always dissolve the salts one by one, fully dissolving each before adding the next
Temperature in °C use warm water (30-40°C) for better dissolution. For concentrates 60-80°C is fine
Reason (optional) NEVER mix concentrated calcium solutions with sulfates and phosphates — a precipitate will form!
Precision use accurate scales (0.01 g for micro, 0.1 g for macro). An error of ±5% is acceptable
Water use reverse osmosis or soft water. Hard water will add extra calcium and magnesium
Comparison use the ready solution within a week. Concentrates keep for months in a dark place
2 Preparing micro complex
The simplest method for small volumes. Suitable for home use.
Pour 4 liters of warm water into the container (leave room for top-up)
Weigh each salt according to the «g/L» column in the table above
Add salts in order, mixing until fully dissolved:
First calcium nitrate (Ca(NO₃)₂)
Potassium nitrate (Yara)
Magnesium sulfate (alt.)
Monopotassium phosphate
EC Calculator
Add the micronutrients (dissolved separately in a small amount of water)
Bring to 1 liter
Check EC and pH, adjust if necessary
3 Preparing concentrate
Concentrates are convenient for preparing solution repeatedly. Usually a x100 or x200 concentration is made.
Concentrate B
Contains calcium and part of the nitrogen. Volume 1 liter at x100:
Potassium nitrate tech.
Iron chelate (Fe-DTPA or Fe-EDTA) can be added
Concentrate B
Contains phosphates, sulfates, other elements. Volume 1 liter at x100:
Potassium nitrate
Potassium sulfate
Monopotassium phosphate
Potassium sulfate (Yara)
Microelements
Copy add 10 ml of each concentrate per 1 liter of water (at x100). First A, stir, then B.
4 My concentrates (g/L)
A mono-concentrate is a solution of a single salt. It gives maximum flexibility in adjusting the recipe.
Preparing concentrate
Density: you can change element ratios without recalculating the whole recipe
pH Adjustment easily add a missing element based on analysis results
Density: Select concentrate to apply or edit
Precision measure liquid more precisely than weighing small amounts of dry salts
Prepare
Determine the concentration (g/l) for each salt — see the «g/l» column in the table
Mark a line on the container (usually 0.5L or 1L)
Pour into container
Pour hot water
until completely dissolved
Cool and bring to the mark with cold water
Label the container: salt name, concentration, date
Copy measure out the required amount of ml (see the «ml» column in the table) of each mono-concentrate.
5 Preparing concentrate
A combined approach: store mono-concentrates and assemble A and B before use.
My concentrate
Pour the weighed amount into container of required volume
Add calcium nitrate monoconcentrate (measure by table)
If necessary, add iron chelate monoconcentrate
Bring to 1 liter
My concentrate
Pour the weighed amount into container of required volume
Use concentrate when calculating solution B
Potassium nitrate
Potassium sulfate
Monopotassium phosphate
Potassium sulfate
Microelements
Fill with water and bring to mark
Tips this approach lets you quickly reassemble concentrates for a different recipe without preparing the salts again.