Chelated iron DTPA 11%: ochre-yellow powder shown in a laboratory dish

Chelated iron (iron chelate) DTPA 11%

$10.00

Weight	Price	Price per kg	vs 100 g
100 g	$10.00	$100.00	—
500 g	$23.00	$46.00	−54 %
1 kg	$38.00	$38.00	−62 %

$3.33 × 3 with no fees Klarna.

This 11% DTPA chelated iron corrects iron deficiencies in plants, in aquaponics as in hydroponics, and it keeps the iron available to the plant from pH 4 to 7.5 without colouring the water. This water-soluble powder is dosed at about 18 g per 1,000 L every 2 to 3 weeks, a dose that is safe for fish.

Ref. FER-DTPA-11-100·Chelated iron

Weight : 100 g

100 g

500 g

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The summary

What it is: iron chelated with DTPA, at 11% iron, as a water-soluble powder, to correct iron chlorosis in aquaponics and hydroponics.
For which pH: effective from pH 4 to 7.5, whereas EDTA stops holding the iron beyond 6.5. Above 7.5, you need EDDHA.
What sets it apart: it does not colour the water. EDDHA, by contrast, stains the pond a lasting orange-red.
How much to use: about 18 g per 1,000 L to aim for 2 ppm of iron, every 2 to 3 weeks.
And the fish: at the doses used in aquaponics, around 2 ppm of iron, iron chelates are considered harmless.
Sizes and shipping: 100 g, 500 g or 1 kg, dispatched from France.

Versatile iron chelate, active up to pH 7.5, without discolouring the pond water

DTPA 11% chelated iron keeps iron dissolved and available to plants in water where it would otherwise have precipitated. It is the remedy for iron chlorosis, which affects your young leaves first: the leaf blade turns yellow while the veins stay green. The guide iron deficiency in aquaponics explains the diagnosis before you buy.

⚙️ The role of chelation

Iron is one of the elements that an aquaponic system does not supply in sufficient quantity. Fish feed provides too little of it, and at the pH of a balanced tank, often between 6.4 and 7.5, free iron precipitates as unusable hydroxide. Chelation encloses the iron atom in an organic molecule that stops it reacting with the water. The chelating agent acts as a carrier: it delivers the iron to the roots without being a nutrient itself. DTPA holds it up to pH 7.5 and carries almost twice as much per gram as EDDHA. You can compare the three chelates figure by figure.

🎯 Dose and frequency

The dose is calculated on the actual volume of water in circulation, grow beds and sump included. As the product contains 11% iron, 18 g supplies a little under 2 g of elemental iron, or about 2 mg per litre in 1,000 L. For a 600 L system, you therefore weigh out roughly 11 g, which you dissolve in a litre of system water before pouring it all into a well-mixed area, with the pump running. The dose calculator does this calculation for your exact volume.

The target

Aim for between 2 and 3 ppm of iron in the water. Symptoms appear below about 1.5 ppm.

The dose

About 18 g per 1,000 L brings the water to 2 ppm, since the powder is 11% iron.

The rhythm

Top up every 2 to 3 weeks. Iron gets used up and breaks down.

The action

Dissolve the powder in a little system water, then pour it into the sump.

The test that sets the dose

An iron test tells you the actual iron content of your water, whereas the correction only shows on new growth after a few days to 2 weeks. Measure before each dose: that way you know whether the level is staying within the target of 2 to 3 ppm or whether the dose needs adjusting. If your pH is above 7.5, you need EDDHA 6%.

Switch off the UV lamp after each iron dose

DTPA iron is photodegradable: ultraviolet radiation breaks the bond between the iron and its chelating agent, and the released iron precipitates before it reaches the roots. If your system has a UV steriliser, switch it off for 6 to 12 hours after each dose, long enough for the plants to take it up. A reservoir in direct sunlight also benefits from some shade.

🌿 Iron in an aquaponic system

In aquaponics, this deficiency is permanent: fish feed supplies very little iron, so a regular supply of chelated iron is part of routine management. The pH of such a system is most often kept between 6.4 and 7.5, a compromise between the nitrifying bacteria, which prefer slightly alkaline water, and the plants, which absorb nutrients better in slightly acidic water. DTPA suits this range, since it holds iron up to pH 7.5 without colouring the water for the fish. A dose every 3 weeks is generally enough to maintain 2 mg of iron per litre, and the iron test tells you when the level drops below 1.5 mg before the young leaves turn pale.

Technical specifications

The essentials

Iron content: 11% FeIron fully chelated by DTPA, i.e. 110 g of iron per kilo of product.
Chelating agent: DTPADiethylenetriaminepentaacetic acid. It is what protects the iron from precipitating.
Effective pH range: pH 4 to 7.5Above 7.5, switch to EDDHA: DTPA would release its iron.
Water discolouration: NoneThat is the main practical difference from EDDHA, which tints the water orange-red.
Target in the water: 2 to 3 ppm of ironDeficiency symptoms appear below about 1.5 ppm.
Maintenance dose: 18 g per 1,000 LTo aim for 2 ppm of iron, every 2 to 3 weeks.

Use and precautions

Root application: In the sump or the tankDissolve first in a little system water, then pour into a well-circulated area.
Foliar application: About 0.5 g per litreIndicative interval of 5 to 7 days, on foliage that is already chlorotic.
UV sensitivity: PhotodegradableSwitch off the UV steriliser 6 to 12 hours after the addition, or shade the reservoir.
Safe for fish: Safe at normal dosesAround 2 ppm of iron. Shock doses have no place in a living tank.
Solubility: Water-solubleSoluble powder, to be dissolved in a little system water before adding.
Response time: Visible on the new shootsA heavily faded leaf is slow to green up again: judge the correction by the new growth.

Packaging and storage

Available sizes: 100 g, 500 g, 1 kgThe price per kilo falls as the capacity increases.
Storage: Store somewhere dry, cool and sealedThe powder is hygroscopic: a badly resealed sachet clumps together and is hard to weigh.

To budget for separately

Iron test: Colorimetric iron test
Kitchen scales: Weighed to the nearest gram

8 further specifications are available in the detailed view.

In the box

1 pack of DTPA 11% chelated iron, water-soluble powder, in the size of your choice

Iron content, pH range, ecotoxicity and storage conditions recorded on 25/08/2026 from chelate manufacturers' technical data sheets. Iron target and pH of aquaponic systems: FAO guidelines.

DTPA, EDDHA or EDTA: which one for your water

All three carry the same iron. What sets them apart is the pH up to which they hold, the amount of iron per gram, and whether or not they colour the pond water.

Each chelating agent holds iron up to a certain pH, and no further Above its limit, the chelate releases the iron, which precipitates as unusable hydroxide. Measure your pH before choosing: it is the figure that separates the three forms.

	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 DTPA 11 %Your choice	7,5	Yes	11 %	Yes	18 g	$23.00	4 to 7.5
Chelated iron (iron chelate) EDDHA 6%Your choice	9	Yes	6 %	No	33 g	$20.00	4 to 9
Chelated Iron EDTA 13%Your choice	6,5	No	13 %	Yes	15 g	$17.00	4 to 6.5

DTPA 11 %Recommended

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

Chelated Iron EDTA 13%

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

pH limits recorded on 25/08/2026 from chelate manufacturers' technical data sheets. Quantities per 1,000 L calculated from the iron content of each product.

Estimate your
delivery time

A lightweight, non-fragile product, dispatched by tracked parcel from France. Exact shipping costs and final delivery times are shown at checkout once your address has been entered: they depend on the format ordered and the carrier selected. 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

How much DTPA chelated iron is needed for 1,000 litres?

My pH is 7.8, will DTPA be enough?

Does my UV lamp destroy chelated iron?

Does DTPA turn the water red like EDDHA?

How can you tell an iron deficiency from another deficiency?

The signature of iron deficiency is distinctive:

It is the young leaves, at the top of the plant, that lose their colour first.
The leaf blade turns yellow or white, but the veins stay green: this is interveinal chlorosis.
The older leaves, meanwhile, stay green.

If the yellowing starts at the bottom of the plant, it is not iron: look instead at nitrogen or magnesium. The guide to deficiencies in aquaponics explains how to tell these signatures apart.

How long before the leaves turn green again?

Leaves that are already discoloured do not always turn green again, and a badly affected leaf stays pale. The correction should therefore be judged on what grows after the application.

What you need to watch is the new growth. It comes through green within a few days to 2 weeks depending on the species. If it still comes through pale after 3 weeks, look for the cause in the pH or the UV rather than in the dose.

How much DTPA iron for your volume

Enter the total volume of water in your system, including the growing beds. The calculation aims for 2 ppm of iron, the low end of the maintenance range in aquaponics, which runs from 2 to 3 ppm.

Total water volume of the system

50 L10000 L

of DTPA 11% chelated iron per application, to aim for 2 ppm of iron

Gentler maintenance dose, target 1.5 ppm

0 g

Calculation: 2 mg of iron per litre, divided by an iron content of 11%, gives approximately 18 g of product per 1,000 L. Use the actual volume of water, not the nominal volume of the tanks. Repeat every 2 to 3 weeks and switch off the UV steriliser 6 to 12 hours after dosing.

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Chelated iron (iron chelate) DTPA 11%

The summary