Plant Care
- • Climate Control & VPD16
- • Disease & Pest Management14
- • Nutrient Solutions & EC34
- • Plant Health Monitoring7
Inputs
12 parameters · live recalculation on every change
PPM
0ppm
100ppm default
500ppm
L
1L
10L default
1000L
%
1%
5.25% default
15%
0
7 default
14
4
6 default
8
Pro Settings — Lab Controls
MV
400mV
650mV default
900mV
0
0.8 default
1
0.5
1 default
2
Advanced Settings — Deterministic Corrections
G/ML
1g/mL
1g/mL default
1.3g/mL
0.5
0.9 default
1
°C
0°C
20°C default
40°C
0.5
0.95 default
1
Insight band · live
Splitting free chlorine into HOCl + OCl−
The active HOCl share, joined by the weaker OCl− remainder — the running total lands on the 100% speciation split.
- HOCl (active) 96.9% 96.90 %
- + OCl− (weak) 3.1% 100.00 %
- Speciation 100.0% 100.00 %
Free chlorine: 87.6 ppm
HOCl actual: 85.5 ppm
Running total after each term — the final net matches the headline reading in the result card, kept in sync live.
Deterministic model
12 inputs · 10 outputs
Runs 100% in your browser
This is a deterministic model: the same inputs always produce the same outputs, calculated entirely in your browser with nothing sent to any server. It is a planning aid — not a quote, not a dosing instruction, and not a yield forecast. Treat every line as a working estimate and validate it against your own prices and measurements.
It models one system: Make an HOCl solution by volume instead of guessing: bleach mL = target ppm × volume ÷ (bleach % × 10 × density) turns a 5.25% jug into a measured reservoir dose, then the water top-up, the delivered HOCl after stability and mixing derates, and the pH-dependent speciation split at pKa 7.5 follow. The ORP read, pH-adjustment acid, storage stability window, per-liter cost and a green—yellow—red safety band keep the batch honest for root-zone disinfection.
What the HOCl Solution Maker — Hypochlorous Acid & Bleach Dilution Blueprint returns
The engine computes 10 outputs from your 12 inputs. The headline number is Bleach to Add (mL), alongside Water to Add, Actual HOCl, OCl- Share. Every output updates live as you change a parameter.
What it does not do
Outputs depend on the inputs and assumptions shown here. Confirm relevant measurements and local conditions before acting.
STEP 01
Set the recipe: target HOCl ppm and the total batch volume in litres — every downstream line counts off this mass.
STEP 02
Pour the bleach: bleach mL = target × volume ÷ (bleach % × 10 × density), then top the rest with water to the final volume.
STEP 03
Derate the delivered dose: actual HOCl = target × stability × mixing — what the tub receives, not what the label promised.
STEP 04
Split the species at the pH you hold: OCl- share = 1 ÷ (1 + 10^(7.5 − pH)); below pH 7.5 HOCl dominates, above it the weak ion takes over.
STEP 05
Check the meter read: ORP = 650 + (HOCl − 100) × 0.5 − 50(pH − 7) against your ORP target, and add the drop of acid to reach the held pH.
STEP 06
Close the decision: safety band on ppm/ORP/pH, the storage window from temperature, and the bleach cost per litre of finished water.
V_{bleach} = \frac{C \cdot V}{c_b \cdot 10 \cdot \rho}
Bleach to add — target × volume over the stock-jug strength
V_w = V - \frac{V_{bleach}}{1000}
Water to top up — final volume minus the bleach litres
C_{HOCl} = C \cdot f_s \cdot \eta
Delivered HOCl — the target derated by stability and mixing
f_{OCl} = \frac{1}{1 + 10^{pK_a - pH}}, \quad pK_a = 7.5
OCl- share — Henderson-Hasselbalch speciation at pKa 7.5
ORP = 650 + (C_{HOCl} - 100) \cdot 0.5 - 50(pH - 7)
ORP the meter should read — ppm and held pH to millivolts
V_{acid} = |pH_t - pH_w| \cdot V \cdot 0.5 \cdot f_{acid}
pH adjustment — acid millilitres to reach the held pH
t_{days} = 30 \cdot f_s \cdot \left(1 - (T - 20) \cdot 0.02\right)
Storage window — 30 days scaled by stability and heat
\text{green } 50{-}200,\ \text{yellow } 20{-}50 \,|\, 200{-}300,\ \text{red } <20 \,|\, >300 \,|\, ORP > 800
Safety bands — ppm, ORP and held pH
Stock labels split two ways: consumer bleach is printed % w/v — 5.25% means 52.5 g of chlorine per litre regardless of the jug weight — so the default density of 1.0 reads 100 ppm in 10 L as the classic 19.0 mL; set 1.08 and the same label is treated as % w/w, pushing the mass every mL carries and trimming the dose ~8%. Pool-grade concentrates that print % w/w are the case for the higher density. Pick the convention your label actually uses.
Delivered HOCl never equals the target: at the stability 0.9 and mixing 0.95 defaults a 100 ppm recipe lands 85.5 ppm — the tool says so in the main card instead of printing the label number back at you.
The speciation follows the archived hypochlorous-acid engine exactly: fraction HOCl = 1 − 1/(1 + 10^(pH − 7.5)) at pKa 7.5, so at pH 6.0 the batch is ~97% the strong acid and at pH 8.0 ~76% of the same ppm sits as the weak OCl- ion.
ORP is a proxy, not a purity test: the locked curve 650 + (HOCl − 100) × 0.5 − 50(pH − 7) means a clean low-pH batch reads high even at modest ppm, and any read above 800 mV trips a red band on its own — target the meter, then confirm with a free-chlorine strip.
Free-chlorine strips read HOCl plus a slice of OCl-: the pH panel shows free chlorine = HOCl × (1 + OCl- ratio × factor), so at pH 6 a strip under-reads true HOCl by only a couple of percent while at pH 8 it prints a number that flatters a weak disinfectant.
The 30-day stability window at 20 °C halves as temperature climbs through the model t_days = (1 − (T − 20) × 0.02), and the cost line is bleach-only at $0.90/L retail — water is free and the per-litre chlorine share of a 100 ppm batch rounds to under $0.001.
- Bleach volume: V = target ppm × volume L ÷ (bleach % × 10 × density) — the archived sterilization and dilution engines reduced a concentrated stock to a safe working ppm through the C1V1 = C2V2 dilution rule; this arm resolves the rule into millilitres of jug to pour.
- Delivered HOCl: C = target × stability × mixing — the archived root-rot tool sized oxidizer against a 30–50 ppm root-zone target and matched it to an ORP baseline, never a raw label strength; the two derates keep the delivered line honest.
- pH speciation: HOCl fraction = 1 − 1/(1 + 10^(pKa − pH)), pKa 7.5 — the archived hypochlorous engine computed exactly this Henderson-Hasselbalch split at pH 4–9 and reported the inactive OCl- share beside the active acid.
- ORP curve: ORP = 650 + (HOCl − 100) × 0.5 − 50(pH − 7) — the archived root-rot baseline held sanitation to an optimal oxidation-reduction potential; this arm derives a millivolt read from ppm and pH so dosing targets the meter, not the jug.
- pH adjustment: V Acid = |pH target − pH source| × volume × 0.5 × acid factor — the archived ph-adjuster scaled acid millilitres against reservoir volume and pH swing; the factor folds in your actual acid strength.
- Stability and cost: t days = 30 × stability × (1 − (T − 20) × 0.02); cost/L = bleach litres × price ÷ volume — warm reservoirs decay chlorine faster and the bleach share of the batch price is the only material cost line, both carried from the running-cost discipline.
This model combines the earlier Hocl-calculator, Hypochlorous-acid-mixer, Bleach-dilution-calculator models.
Q1: How to make HOCl solution from bleach? ▾
Measure, do not guess: bleach mL = target ppm × volume L ÷ (bleach % × 10 × density), then top up the rest with water. For 10 L at 100 ppm from a 5.25% jug treated as % w/v (density 1.0) that is 1000 ÷ 52.5 = 19.0 mL of bleach into a 10 L bucket. The delivered HOCl is lower than the target once stability (fresh jug ≈ 1.0, aged jug 0.5–0.9) and mixing ~0.95 derate it, and the pH you hold decides how much of that chlorine is the active acid — below pH 7.5 HOCl dominates, above it the weak OCl- ion takes over.
Q2: Hypochlorous acid mixing calculator: how does the math work? ▾
The engine runs five honest lines: bleach volume from the dilution rule C1V1 = C2V2 resolved to millilitres, water top-up to the final volume, delivered HOCl = target × stability × mixing, the Henderson-Hasselbalch speciation split at pKa 7.5 that divides HOCl from OCl- at the pH you hold, and the ORP read = 650 + (HOCl − 100) × 0.5 − 50(pH − 7). It also prices the batch: at the $0.90/L bleach retail assumption a 100 ppm solution carries under $0.001 of chlorine per litre, so the expensive part is the jug, not the dose.
Q3: Bleach dilution calculator ppm: how much bleach do I add per gallon or litre? ▾
Volume scales linearly with the dilution: required mL = target ppm × volume ÷ (bleach % × 10 × density). Per litre at 5.25% w/v that is target ÷ 52.5 mL — so 100 ppm needs 1.90 mL per litre, 200 ppm needs 3.81 mL per litre, 20 ppm needs 0.38 mL per litre. For a 50 L reservoir a 200 ppm shock takes 200 × 50 ÷ 52.5 = 190.5 mL (+ density if your label is % w/w); the tool computes the exact number for your jug strength and top-up volume.
Q4: Is HOCl pH dependent? Which pH keeps it as hypochlorous acid? ▾
Completely. Sodium hypochlorite equilibriates between strong HOCl and the weak OCl- ion with a pKa of 7.5: at pH 7.5 the batch is 50/50, at pH 6.0 roughly 97% of the chlorine is active HOCl, and at pH 8.0 about 76% has flipped to the weak ion, which disinfects at a fraction of the rate. Hold your sanitising batch below pH 7 — practically around 6 — so the same ppm does far more work; the pH panel shows the exact HOCl/OCl- split at the held pH.
Q5: What ORP should hypochlorous acid solution read, and when is it unsafe? ▾
The locked read is ORP = 650 + (HOCl − 100) × 0.5 − 50(pH − 7): a 100 ppm batch at pH 6 reads about 693 mV. Root-zone sanitation is typically run toward a 600–750 mV baseline. The tool flags red below 20 ppm ORP aside, above 300 ppm, above 800 mV, or outside pH 4–8 — an ORP meter alone never approves a batch, so confirm with the ppm line and the pH band before anything touches roots.
Q6: How long does diluted HOCl stay effective and how do I price it per litre? ▾
Diluted chlorine decays faster than the jug: the model starts at a 30-day usefulness window at 20 °C and shrinks it as the batch warms — t_days = 30 × stability × (1 − (T − 20) × 0.02) — so a 30 °C grow room roughly halves the shelf life. Make small batches for the week, store them dark and cool, and mind the per-litre cost: bleach at $0.90/L retail puts the chlorine share of a 100 ppm batch under $0.001 per litre, which is why the jug strength and the dose, not the water, are what cost money.