Yellow microgranulated chelated iron EDTA powder spread in a glass dish, on a white background

Chelated Iron EDTA 13%

7,50 €

Weight	Price	Price per kg	vs 100 g
100 g	7,50 €	75,00 €	—
500 g	14,50 €	29,00 €	−61 %
1 kg	22,90 €	22,90 €	−69 %

This EDTA iron chelate supplies 13% iron and corrects iron chlorosis in water kept between pH 4 and 6.5. The powder dissolves completely, does not colour the water and is harmless to fish at the recommended doses.

Ref. FER-EDTA-13-100·Chelated iron

Weight : 100 g

100 g

500 g

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The summary

What the sachet contains: 13% iron chelated with EDTA, a 100% water-soluble micro-granulated powder.
For which water: water kept between pH 4 and 6.5, controlled hydroponics, rainwater, freshwater aquaponics.
How much to use: 10 g per 1,000 L as a preventive measure, 15 g for established chlorosis, every 2 to 3 weeks.
The UV lamp: the chelate breaks down in light, so switch off the steriliser for 6 to 12 hours after each dose.
What it changes in the water: no colouring, no effect on pH, dissolves without residue.
Pack sizes: 100 g, 500 g and 1 kg, shipped from France.

13% iron chelate, for freshwater and systems kept below pH 6.5

Chelated iron EDTA 13% supplies plants with usable iron in water kept between pH 4 and 6.5, as in hydroponics, with rainwater or in freshwater aquaponics. The dose is 10 g per 1,000 L as a preventive measure and 15 g for established chlorosis. Above pH 6.5, EDTA releases its iron.

EDTA chelated iron is a mineral supplement containing 13% iron, the highest content of the three common iron chelates. The chelating agent encloses the iron atom in a molecule that stops it reacting with water and precipitating as hydroxide, and it does this from pH 4 to 6.5. Beyond that, the iron detaches and is no longer available to plants, which makes the pH of your water the first criterion when choosing.

💧 Water kept below pH 6.5

This form of iron suits water that you keep, naturally or deliberately, below 6.5. That is the case with hydroponics, where the nutrient solution is most often managed between pH 5.5 and 6.5, with a tank filled with rainwater, which is very low in minerals, or with reverse osmosis water. In an aquaponic system, nitrification releases acidity and gradually lowers the pH when the top-up water is soft; conversely, hard tap water raises it with each top-up. If your pH regularly exceeds 6.5, EDTA will release its iron between two measurements, and the comparison of the three chelates then shows which form holds at a higher pH.

Measure the pH before dosing

Pick up a liquid pH test kit at the same time. It is the only figure that tells you whether this form of iron will hold up in your set-up, and it is read in 5 minutes. Add an iron colorimetric test if you want to set the dose by a measurement rather than by the spoonful.

🧮 How much to use

The dose is calculated on the actual volume of circulating water, grow beds included. As the product contains 13% iron, 15 g supplies roughly 2 g of metallic iron, i.e. 2 mg per litre in 1,000 L. For a 300 L hydroponic system, you therefore weigh out 3 g as a preventive dose or 4.5 g for established chlorosis, and dissolve it in half a litre of water before pouring it in, with the pump running.

The target

Aim for between 2 and 3 ppm of dissolved iron in the system water.

As a preventive measure

Allow 10 g per 1,000 L, or 1.3 mg of iron added per litre, before a single leaf starts to pale.

For a deficiency

Move up to 15 g per 1,000 L, or 2 mg per litre, once chlorosis is already visible.

As a foliar feed

Spray 1 to 2 g per litre of spray mixture onto the foliage.

Switch off the UV steriliser for 6 to 12 hours

EDTA iron is photodegradable: ultraviolet light breaks the bond between the iron and its chelating agent, and the freed iron precipitates before it reaches the roots. If your circuit has a UV lamp, switch it off for 6 to 12 hours after each dose, long enough for the plants to take the iron up. A reservoir exposed to direct sunlight is also best shaded, since daylight has the same effect.

🐟 Fish, bacteria and iron

In your system, the fish, the bacteria and the plants share the same water, and a dose of iron affects all three. It does not change the pH, it does not harm the bacteria in the biofilter, and it is harmless to fish at the usual doses, around 2 to 3 ppm. The guide to iron deficiency in aquaponics helps you tell an iron deficiency from a nitrogen deficiency, or from a root problem, before you dose anything.

Technical specifications

The essentials

Iron content: 13% chelated FeThat is 130 g of iron per kilo of product
Chelating agent: EDTAIt is what keeps the iron dissolved instead of letting it precipitate as hydroxide
Active pH range: pH 4 to 6.5Above 6.5, the iron detaches from the chelating agent and is no longer available to plants
Water discolouration: NoneThe tank water stays clear after adding it
Solubility: 100% water-solubleMicro-granulated powder, to be dissolved in a little water before pouring
UV sensitivity: PhotodegradableSwitch off the UV steriliser 6 to 12 hours after the application

The dose and the frequency

Preventive dose: 10 g per 1,000 LAdds 1.3 mg of iron per litre, in a system that still contains about 1 mg, before any symptom appears
Correction dose: 15 g per 1,000 LAdds 2 mg of iron per litre, when chlorosis is already visible on the young leaves
Foliar application: 1 to 2 g per litreOn foliage that is already chlorotic, the symptoms fade within a few days
Target dissolved iron: 2 to 3 ppmThat is 2 to 3 mg of iron per litre of system water
Frequency: Every 2 to 3 weeksIron is consumed and breaks down, so the supply must be topped up
Storage: Kept away from damp, in a cool placeThe bag reseals after each use

Compatibility

Fish and biofilter: Safe at normal dosesAt around 2 to 3 mg of iron per litre, the nitrifying bacteria are not affected.
Effect on pH: No noticeable effectThis product is not a pH corrector.

To budget for separately

pH test: pH water test dropsIt is the figure that tells you whether this form of iron will hold up in your system
Kitchen scales: Weighed to the nearest gram

8 further specifications are available in the detailed view.

In the box

1 pack of EDTA 13% chelated iron powder, in the size ordered

Iron content, pH range, solubility, sensitivity to ultraviolet light and storage: product data sheet, consulted on 25/08/2026, and pH limits taken on the same date from chelate manufacturers' data sheets.

EDTA, DTPA or EDDHA: which one for your water

All three carry the same iron. What sets them apart is the pH above which they stop holding it, the amount of iron per gram, and whether or not they colour the water.

Beyond its limit, a chelate releases its iron The iron released precipitates as hydroxide and stops being available to plants. The water you pour in therefore determines which form to buy, well before the iron content does.

	Upper pH limit	Still effective at pH 7	Iron content (%)	Leaves water colourless	Powder for 1,000 L at 2 mg of iron per litre (g)	Price	pH range where iron remains available
Recommended EDTA 13 %Your choice	6,5	No	13 %	Yes	15 g	22,90 €	4 to 6.5
Chelated iron (iron chelate) DTPA 11%Your choice	7,5	Yes	11 %	Yes	18 g	32,90 €	4 to 7.5
Chelated iron (iron chelate) EDDHA 6%Your choice	9	Yes	6 %	No	33 g	26,90 €	4 to 9

EDTA 13 %Recommended

pH stability

Upper pH limit6,5

Still effective at pH 7No

Concentration and quantity

Iron content (%)13 %

Leaves water colourlessYes

Powder for 1,000 L at 2 mg of iron per litre (g)15 g

Price

Activity range

pH range where iron remains available4 to 6.5

Chelated iron (iron chelate) DTPA 11%

pH stability

Upper pH limit7,5

Still effective at pH 7Yes

Concentration and quantity

Iron content (%)11 %

Leaves water colourlessYes

Powder for 1,000 L at 2 mg of iron per litre (g)18 g

Price

Activity range

pH range where iron remains available4 to 7.5

Chelated iron (iron chelate) EDDHA 6%

pH stability

Upper pH limit9

Still effective at pH 7Yes

Concentration and quantity

Iron content (%)6 %

Leaves water colourlessNo

Powder for 1,000 L at 2 mg of iron per litre (g)33 g

Price

Activity range

pH range where iron remains available4 to 9

pH limits recorded on 25/08/2026 from Van Iperen and Custom Hydro Nutrients. Quantities for 1,000 L calculated on the iron content of each product.

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Powder shipped in a sealed sachet, as an ordinary parcel from France, with a choice of pick-up point or home delivery by Colissimo during checkout. The exact cost is shown in your basket once you have entered your address.

Frequently asked questions

6 questions

6 key questions

At what pH does EDTA stop holding the iron?

How much to add per 1,000 litres?

The usual reference dose is 10 to 15 g per 1,000 litres. Here is how to proceed:

Work out the volume of water actually in circulation, grow beds included, and not the nominal volume of the tanks.
Weigh out 10 g for maintenance, when the test still reads about 1 mg of iron per litre, as they add 1.3. Weigh out 15 g, which adds 2 mg per litre, to correct visible chlorosis.
Dissolve the powder in half a litre of water, stirring until the grains disappear.
Pour it in with the pump running, to distribute the product throughout the circuit.
Aim for 2 to 3 ppm of dissolved iron, and repeat every 2 to 3 weeks.

Should you switch off the UV lamp after dosing?

Is it safe for the fish?

Can it be sprayed on the leaves?

Does EDTA colour the water or shift the pH?

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Chelated Iron EDTA 13%

The summary