Metal Sequestrant Calculator

Calculator inputs

Enter your water volume, metal levels, and product details.

Tip: Use lab results when possible.

Water volume

Enter a valid volume.

Used for mixing tank, tote, or irrigation reservoir.

Water pH

Higher pH can weaken some chelators.

Hardness (mg/L as CaCO₃)

Hard water may require a higher safety factor.

Iron (Fe) mg/L

Manganese (Mn) mg/L

Copper (Cu) mg/L

Fe binding ratio (mg active per mg Fe)

Common ranges: 2–5 depending on product.

Mn binding ratio (mg active per mg Mn)

Mn can require slightly more active ingredient.

Cu binding ratio (mg active per mg Cu)

Use conservative ratios for mixed-metal water.

Safety factor

Adds buffer for water variability and losses.

Re-dose interval (days)

Shorter intervals for outdoor tanks and heat.

Product form

Choose a product form.

Active ingredient (%)

Use the label’s active percentage or assay value.

Liquid density (g/mL)

If unknown, leave default (typical 1.0–1.2).

Dose/output unit

Choose the unit you measure at home.

Unit price (PKR per unit)

Optional: estimates dose cost in PKR.

Notes (optional)

Saved into CSV/PDF exports.

Clear results

Safety note: always follow the product label, wear gloves, and avoid mixing incompatible chemicals.

Example input sets

Use these to test the calculator and understand outputs.

Scenario	Volume	Fe (mg/L)	Mn (mg/L)	Cu (mg/L)	Active %	Safety	Notes
Rain tank with light staining	1,000 L	1.2	0.10	0.02	40%	1.15	Good baseline for routine dosing.
Well water, drip clog risk	500 US gal	3.5	0.40	0.05	60%	1.30	Consider filtration plus sequestrant.
Greenhouse reservoir	2 m³	0.8	0.05	0.03	35%	1.20	Re-dose more often in warm weather.

Formula used

This calculator estimates active ingredient needed to bind metals.

1) Convert volume to liters

Liters = Volume × unit factor

2) Compute active dose per liter

Active(mg/L) = (Fe×R_Fe + Mn×R_Mn + Cu×R_Cu) × Safety

Fe, Mn, Cu are in mg/L. Ratios are mg active per mg metal.

3) Total active needed

Active(g) = Active(mg/L) × Liters ÷ 1000

4) Convert active to product amount

Product mass(g) = Active(g) ÷ (Active% ÷ 100)

Liquids convert mass to volume using density: mL = grams ÷ density(g/mL).

How to use this calculator

Measure your mixing tank volume and pick the correct unit.
Enter metal levels from a lab report or test kit.
Keep binding ratios at defaults unless your label states otherwise.
Set product form, active percentage, and density if liquid.
Press Calculate to show results above the form.
Use Download CSV or Download PDF for records.

Practical tip: If you still see staining, raise the safety factor slightly, re-test metals, and confirm pH is within your product’s working range.

Why sequestration matters in irrigation

Dissolved metals can oxidize, form deposits, and stain leaves, benches, and emitters. Even low iron levels around 0.3–1.0 mg/L may leave visible residue over repeated watering. Manganese can darken filters and tubing, while copper may create blue-green staining. A sequestrant keeps metals in solution carefully long enough for filtration, flushing, or safe application.

Interpreting mg/L test results

The calculator uses mg/L (ppm) for iron, manganese, and copper. Multiply each metal by its binding ratio to estimate the active ingredient needed per liter. Total active is then scaled by volume; for example, 1 mg/L across 1,000 L equals 1,000 mg (1 g) before safety factor. Accurate volume measurement reduces under-dosing and helps protect micro‑emitters.

Choosing ratios and a safety factor

Ratios represent how many milligrams of active material are assigned to each milligram of metal. Products vary by chemistry and purity, so start with conservative ratios if you lack a label guideline. The safety factor adds a buffer for pH drift, hardness, temperature swings, and organic load; 1.10–1.30 is common for mixed sources. If water changes seasonally, keep notes.

Converting active grams into product dose

Active grams are divided by the product’s active percentage to estimate total product mass. Liquids then convert grams to mL using density (g/mL), which is why a 1.10 density yields fewer mL than a 1.00 density for the same mass. Powders remain in grams or kilograms,. Select the output unit you actually measure to reduce dosing errors.

Using results for planning and records

Pair the dose result with a re-dose interval to manage outdoor tanks, heat,. Exporting CSV/PDF helps track seasonal trends, compare products, and estimate costs per treatment. If staining persists, retest metals, verify pH range, and adjust the safety factor before increasing ratios. For new products, run a small jar test to confirm compatibility with fertilizers and injectors.

What does the calculator output represent?

It estimates the amount of product needed to provide enough active ingredient to bind iron, manganese, and copper in your chosen water volume, including your safety factor.

Can I use ppm instead of mg/L?

Yes. For dilute water tests, ppm and mg/L are effectively equivalent. Enter your results as shown on the lab report or test kit, then keep units consistent.

Why does pH matter for sequestrants?

Some chelating agents work best within a specific pH range. Higher pH can reduce binding strength and increase precipitation risk, so the calculator flags high pH as a caution.

Should I raise the safety factor for hard water?

Often, yes. High hardness can compete with binding or increase deposits. If hardness is above about 250 mg/L as CaCO₃, consider a modest safety increase and verify performance.

How do I set the active percentage?

Use the label’s stated active content or assay value. A higher percentage means less product is needed for the same active grams, which lowers volume or mass dosed.

Is the cost estimate required?

No. If you enter a unit price, the calculator multiplies it by the estimated product amount in your selected unit. Leave it blank to skip cost planning.