White bottle of liquid EDDHSA chelated iron next to a beaker of deep red solution

Liquid chelated iron EDDHSA 6%

¥1,800

Format	Price	Price per L	vs 250 ml
250 ml	¥1,800	¥7,200	—
500 ml	¥2,900	¥5,800	−19 %
1 L	¥4,600	¥4,600	−36 %
5 L	¥10,900	¥2,180	−70 %

¥600 × 3 with no fees Klarna.

This liquid chelated iron at 6% corrects iron deficiencies in aquaponics and hydroponics crops, and remains available up to pH 9, including in hard water. It is dosed by the millilitre, with no powder to weigh or dissolve.

Ref. FER-EDDHSA-6L-250·Deficiency corrector

Format : 250 ml

250 ml

500 ml

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The summary

What you receive: a liquid EDDHSA chelated iron at 6%, providing 75 g of iron per litre of product.
For which water: it keeps iron plant-available up to pH 9, beyond the pH 7.5 limit of DTPA.
How much to add: 27 ml in 1,000 litres raises the iron content by 2 mg per litre.
With fish: the standard dose remains 3 times below the highest concentration tested without acute toxicity in trout.

Liquid chelated iron stable up to pH 9, dosed to the millilitre in aquaponics

This liquid chelated iron supplies your crops with the iron that aquaponic system water does not provide on its own. The iron is bound to EDDHSA, a chelating agent that prevents it from precipitating and keeps it in a form that roots can absorb, up to pH 9. The product contains 6% iron, equivalent to 75 g per litre, and is measured by the millilitre.

Without a chelate, dissolved iron reacts with hydroxide ions as soon as the pH rises, forming an insoluble hydroxide that the plant can no longer absorb. Your leaves will then yellow in water that nonetheless contains iron. Each chelating agent protects iron up to a given pH, and it is this upper limit that guides your choice between the forms you can compare criterion by criterion.

🧪 EDDHSA versus other chelates

Up to pH 9

EDDHSA keeps iron soluble across the full pH range of an aquaponic system, including when hard water pushes pH above 7.5.

Further than DTPA

DTPA stops protecting iron around pH 7.5 and EDTA around 6.5, which limits both forms to soft or corrected water.

Like EDDHA, in liquid form

EDDHA covers the same pH range in powder form. EDDHSA, around three times more soluble, can be poured in directly.

A brown tint

The iron-EDDHSA complex is dark red to brown. Its colour remains subtle at maintenance doses and becomes visible as the concentration increases.

🐟 Iron in an aquaponic system

Fish food does a poor job of meeting your plants' iron requirements, which is why iron, along with potassium and calcium, is among the most common deficiencies in aquaponics. The target level is around 2 mg of iron per litre. At this dose, the product is present at approximately 33 mg per litre of water, whereas acute toxicity trials on rainbow trout and daphnia reached no toxicity threshold up to 100 mg per litre, a safety margin of a factor of 3 for your fish. The guide to iron deficiency in aquaponics covers the cases where iron is not the cause.

Add the iron on its own, never alongside another concentrate

Never mix the undiluted product with a highly alkaline solution or with a phosphate-rich concentrated fertiliser, as the iron would precipitate before reaching the system water. Add it on its own, directly into a well-agitated area, then allow the water to homogenise before adding anything else. Reseal the bottle after use and store it away from light, as the iron-EDDHSA complex is photosensitive.

Test iron levels before each addition

A drop-based iron test tells you the actual concentration in your water, and it is the difference from the 2 mg per litre target that determines how much to add. This way you avoid a needless dose when the level is still adequate, and you can confirm the correction the following day. In a tank of a few hundred litres, where you are measuring just a few millilitres, this test makes every addition reproducible. Above 1.5 mg per litre, the last field on the colour chart, diluting the sample by half with distilled water extends the readable range up to the target.

💧 Dosing to the millilitre

With a density of 1.25, each millilitre of product delivers 75 mg of iron. In 1,000 litres of water, 27 ml therefore raises the iron content by 2 mg per litre, and 40 ml raises it by 3 mg per litre. In a 100-litre tank, these volumes become 2.7 and 4 ml respectively, amounts that a graduated syringe measures far more accurately than a cap. Test the iron level first, then dose with the pump running, calculating based on the volume of water actually circulating in your system, grow beds included.

🌿 Signs of an iron deficiency

Iron deficiency shows first on young leaves at the tops of the stems. The blade turns pale then yellow while the veins remain green, creating a green network on a yellow background: this is iron chlorosis. Older leaves retain their colour for a long time, as iron is not very mobile within the plant. Yellowing that starts at the bottom of the plant points more towards nitrogen, magnesium, or potassium, and the guide on identifying deficiencies will help you tell them apart.

Technical specifications

The essentials

Chelating agent: EDDHSACheck the full abbreviation: EDDHA, one letter different, is a powder.
Iron content: 6%, i.e. 75 g per litreDensity of 1.25: one millilitre contains 75 mg of iron.
pH range: pH 4 to 9Above 7.5, DTPA can no longer hold the iron; EDDHSA keeps it soluble.
Shape: Dark red to brown liquid
Solubility: Approximately 3 times that of EDDHA
Organic farming: Approved for organic use (UAB)European Regulations 2018/848 and 2021/1165.

Dosage and use

Target level in aquaponics: 2 to 3 mg of iron per litre
Dose for 1,000 L: 27 ml for 2 mg/LThat is 2.7 ml per 100 litres, to be measured out with a syringe.
Application method: Neat, in a well-circulated zonePump running, no prior dilution.
Frequency: Based on the iron readingCheck the level every 2 to 3 weeks, before each application.

Safety and storage

Acute toxicity, trout: LC50 greater than 100 mg/LA dose of 2 mg of iron per litre corresponds to 33 mg of product per litre.
Acute toxicity, daphnia: EC50 greater than 100 mg/L48-hour measurement on Daphnia magna.
Storage: Sealed, away from lightThe iron-EDDHSA complex breaks down in light.
Incompatibilities: Strong bases, concentrated phosphatesNever pour it into a stock solution that already contains some.

To budget for separately

Iron test: Colorimetric iron test
Graduated syringe: 5 or 10 ml syringe

8 further specifications are available in the detailed view.

In the box

1 bottle or container of liquid chelated iron EDDHSA 6%, in the chosen size

Iron content, density, pH range, colour, incompatibilities and organic certification status: product technical data sheet, checked on 01/10/2026. Solubility: Chemical Stability of the Fertilizer Chelates Fe-EDDHA and Fe-EDDHSA over Time (2021). Toxicity: ECHA dossier on Fe-EDDHSA. Target concentration: FAO aquaponics manual (2014).

EDDHSA, EDDHA, DTPA or EDTA: which one for your water

All four supply iron. What sets them apart is the pH beyond which they stop releasing it, followed by the form of the product.

Your pH determines the chelate, your equipment determines the form Beyond its pH limit, a chelate allows iron to precipitate. Measure your pH at its highest point of the day, then make your choice.

	Recommended Liquid chelated iron EDDHSA 6%Your choice	Chelated iron (iron chelate) EDDHA 6%Your choice	Chelated iron (iron chelate) DTPA 11%Your choice	Chelated Iron EDTA 13%Your choice
pH stability
Upper pH limit	9	9	7,5	6,5
Keeps iron available above pH 7.5	Yes	Yes	No	No
Form and dosage
Iron content (%)	6 %	6 %	11 %	13 %
Shape	liquid	powder	powder	powder
Quantity for 2 mg of iron per litre in 1,000 L	27 ml	33 g	18 g	15 g
Leaves water colourless	No	No	Yes	Yes
Price	¥4,600	¥4,900	¥6,000	¥4,200

Liquid chelated iron EDDHSA 6%Recommended

pH stability

Upper pH limit9

Keeps iron available above pH 7.5Yes

Form and dosage

Iron content (%)6 %

Shapeliquid

Quantity for 2 mg of iron per litre in 1,000 L27 ml

Leaves water colourlessNo

Chelated iron (iron chelate) EDDHA 6%

pH stability

Upper pH limit9

Keeps iron available above pH 7.5Yes

Form and dosage

Iron content (%)6 %

Shapepowder

Quantity for 2 mg of iron per litre in 1,000 L33 g

Leaves water colourlessNo

Chelated iron (iron chelate) DTPA 11%

pH stability

Upper pH limit7,5

Keeps iron available above pH 7.5No

Form and dosage

Iron content (%)11 %

Shapepowder

Quantity for 2 mg of iron per litre in 1,000 L18 g

Leaves water colourlessYes

Chelated Iron EDTA 13%

pH stability

Upper pH limit6,5

Keeps iron available above pH 7.5No

Form and dosage

Iron content (%)13 %

Shapepowder

Quantity for 2 mg of iron per litre in 1,000 L15 g

Leaves water colourlessYes

pH ranges sourced from the EDDHSA technical datasheet on 01/10/2026, and from Van Iperen and Custom Hydro Nutrients on 25/08/2026. Quantities calculated on the iron content of each product.

Documents & manuals

Official technical data sheet

It guarantees 6% chelated iron, i.e. 75 g per litre, and specifies a density of 1.25, stability up to pH 9, and products that must not be mixed with it.

PDF · 150 Ko

Download

Estimate your
delivery time

Liquid container, dispatched by tracked parcel from France. The 5 L size is a heavy parcel. Exact shipping costs and final delivery times are shown at checkout once your address has been entered. Outside the European Union, import duties and taxes remain the responsibility of the recipient. Delivery times run from the date of dispatch, excluding public holidays.

Frequently asked questions

6 questions

6 key questions

Is it safe for the fish in an aquaponic system?

Yes, at standard doses. To target 2 mg of iron per litre, the product is present at approximately 33 mg per litre, whereas acute toxicity trials on rainbow trout and daphnia reached no toxicity threshold up to 100 mg per litre.

Calculate the dose based on the volume actually in circulation, including the growing beds, and do not exceed 3 mg of iron per litre. Beyond that, the surplus is no longer of use to the plants and turns the water brown.

How much to add per 1 000 litres?

One millilitre delivers 75 mg of iron. Here is the procedure:

Measure dissolved iron using an iron test kit.
Calculate the gap between your reading and the target of 2 to 3 mg per litre.
Allow 13 ml per 1,000 litres for each milligram to make up — that is 27 ml for 2 mg.
Draw up the required volume in a syringe and pour it into a well-circulated area with the pump running.
Take a new measurement the following day.

What is the difference between EDDHSA and EDDHA?

Form and solubility. EDDHA is sold as a powder and permanently tints the water orange-red. EDDHSA, roughly three times more soluble, is sold as a liquid and is dosed by the millilitre.

pH, on the other hand, separates them little. Both keep iron in solution up to a pH of around 9, beyond the range of DTPA, which is limited to around 7.5, and EDTA, limited to around 6.5. Check the full acronym before ordering, as a single letter sets them apart.

Up to what pH does it remain effective?

How do you recognise an iron deficiency?

Does the product colour the tank water?

How much liquid EDDHSA iron for your water volume

Enter the volume of water actually circulating in your system, growing beds and reservoir included. The calculation is based on a concentration of 75 g of iron per litre of product.

System water volume

50 L5000 L

0ml

to raise the iron content by 2 mg per litre, to be added with the pump running.

To raise the level by 3 mg per litre, for an established deficiency

0 ml

Calculation based on a content of 75 g of iron per litre of product. Adjust using a dissolved iron measurement taken before and after dosing.

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Liquid chelated iron EDDHSA 6%

The summary