1 L bottle of OligoSpectrum, chelated liquid trace elements

500 ml bottle of chelated trace elements for hydroponics

5 L container of OligoSpectrum, orange label

All OligoSpectrum formats lined up, from the 500 ml bottle to the jerry can

Chelated liquid trace elements for hydroponics

5,90 €

Conditionnement	Price	Price per L	vs 500 mL
500 mL	5,90 €	11,80 €	—
1 L	9,90 €	9,90 €	−16 %
5 L	42,90 €	8,58 €	−27 %
10 L	75,90 €	7,59 €	−36 %

1,96 € × 3 with no fees Klarna.

This liquid supplement supplies seven trace elements, including iron, manganese, zinc, and copper in chelated form, to a hydroponic solution or a fertiliser that is lacking them. It is dosed at 2 ml per litre in the reservoir, and can also be applied as a foliar spray to correct a deficiency quickly.

Ref. TA-OLIGO-500·Hydroponic fertiliser

Conditionnement : 500 ml

500 mL

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The summary

What you receive: a bottle of iron, manganese, zinc, copper, boron, molybdenum and cobalt in solution, in your chosen size.
The dose: 2 ml per litre of hydroponic solution or as a foliar spray, 3 ml per litre in soil.
Which fertiliser to use with it: a fertiliser low in trace elements — never a complete fertiliser such as TriPart.
How to choose: the comparison tool shows how it sits alongside chelated iron, which corrects iron alone.

Seven trace elements to complete a hydroponic solution, whether on coco fibre or in soil

In hydroponics, the plant finds in its solution only what you put there: no soil reserves to compensate for a missing element. Trace elements represent only a tiny fraction of what the plant absorbs, yet the absence of just one is enough to hold back its growth. This liquid supplement provides seven of them, and protects four, iron, manganese, zinc and copper, in a chelated form: an organic molecule surrounds them and keeps them dissolved in the solution, where a bare metal ion would eventually precipitate to the bottom of your reservoir.

🧪 Which fertiliser to use with it

This supplement is added to a liquid or powder fertiliser whose formula does not detail trace elements, or contains only a few. It is not added to complete fertilisers from the same range, such as TriPart, DualPart or NovaMax, which already provide a broad spectrum. Its formula also contains an organic pH stabiliser, and it is approved for use in organic farming, which means you can use it on a crop grown under those rules.

Measure the iron before topping up the solution

When young leaves turn yellow, a drop-test iron kit will tell you whether iron alone is the cause. If so, a DTPA chelated iron supplement will correct it directly. If several symptoms are present at once, this supplement covers all the trace elements in a single application, saving you the trouble of identifying which one is lacking.

🌿 What trace elements are for

These elements are needed in minute quantities, on the order of a milligram per litre of solution, but each one governs a specific stage of growth. Most are poorly mobile within the plant: once fixed in a leaf, they are no longer redistributed, so a deficiency first appears on the young leaves at the top. You can recognise it by a leaf blade that pales between veins that remain green, by spots, or by abnormally short internodes. Regular addition to the solution prevents these symptoms from taking hold.

Iron

It plays a role in chlorophyll production. A deficiency appears on young leaves, which turn pale between the veins.

Manganese and zinc

The first contributes to photosynthesis, the second to the production of growth hormones. A deficiency of either shortens internodes and causes leaf spotting.

Molybdenum

It allows the plant to convert nitrate into proteins, which matters in hydroponics, where nitrogen arrives mainly in the form of nitrate.

On a stocked pond, monitor the copper input

At 2 ml per litre, the hydroponic dose, its copper content reaches around 0.2 mg per litre, a level that fish tolerate poorly. On a fish-free system or a decoupled loop, it can therefore be used as in hydroponics. On a stocked pond, it is better to correct iron alone with a DTPA chelated iron, or to reduce the dose significantly while monitoring your fish and testing copper levels with a drop-based copper test kit.

💧 The dose and the technique

In a hydroponic solution or as a foliar spray, the dose is 2 ml per litre. In soil, where some elements bind to soil particles, this rises to 3 ml per litre of irrigation water. For a 20-litre reservoir, you add 40 ml, and a 500 ml bottle prepares 250 litres of solution. Add the supplement with each fresh solution, at the same time as your base fertiliser, then adjust the pH last. It accompanies the crop from cutting through to harvest, in hydroponics, coco fibre and pot growing alike.

Technical specifications

The composition

Iron: 0.1 %, chelatedEssential for the production of chlorophyll
Manganese: 0.025%, chelated
Zinc: 0.01%, chelated
Copper: 0.01%, chelated EDTAAt 2 ml per litre, approximately 0.2 mg of copper per litre: reduce the dose in a stocked pond
Boron: 0.01 %In the form of boric acid
Molybdenum: 0.003%In the form of ammonium molybdate
Cobalt: 0.001%
pH stabiliser: Of organic origin

Use

Hydroponics: 2 ml per litre
Soil growing: 3 ml per litre
Foliar spray: 2 ml per litreOn both sides of the leaves, out of direct sunlight
Storage: 5 years after openingKeep tightly sealed, away from frost

Safety and bottle

Ranking: Not classified as hazardousIn a stocked pond, its dose must be significantly reduced due to copper
Organic farming: Suitable for useRegulations (EU) 2018/848 and 2021/1165
500 ml bottle: 15.9 x 7.4 x 7.4 cm
Manufacturing: France

To budget for separately

Foliar application: A clean sprayerReserved for this use only, with no treatment residue
Iron monitoring: A liquid iron test kit

10 further specifications are available in the detailed view.

In the box

1 bottle of liquid trace elements, in your chosen size: 500 ml, 1 L, 5 L or 10 L

Composition, doses, shelf life, dimensions and classifications recorded on 01/10/2026 from the manufacturer's product sheet and safety data sheet. The copper content at 2 ml per litre is calculated on the guaranteed composition.

All trace elements, or iron alone?

Two supplements for a hydroponic solution. The first covers seven micro-elements; the second corrects iron alone, at high concentration.

Not sure which of these two supplements to choose? One covers seven trace elements in a single application; the other corrects iron alone, at a lower cost.

	Elements supplied	Shape	Iron content	Dose in solution	Foliar spray
Recommended Chelated liquid trace elements forYour choice	Iron, manganese, zinc, copper, boron, molybdenum and cobalt	Liquid, measured in millilitres	0,1 %	2 ml per litre	2 ml per litre
Chelated iron (iron chelate) DTPA 11%Your choice	Iron only	Powder, weighed in grams	11 %	18 g per 1,000 litres	0.5 g per litre

Chelated liquid trace elements forRecommended

Elements suppliedIron, manganese, zinc, copper, boron, molybdenum and cobalt

ShapeLiquid, measured in millilitres

Iron content0,1 %

Dose in solution2 ml per litre

Foliar spray2 ml per litre

Chelated iron (iron chelate) DTPA 11%

Elements suppliedIron only

ShapePowder, weighed in grams

Iron content11 %

Dose in solution18 g per 1,000 litres

Foliar spray0.5 g per litre

Compositions and doses recorded on 01/10/2026 from the manufacturer's data sheet and from the shop's DTPA chelated iron data sheet.

Documents & manuals

Safety data sheet, in French

The data sheet covers the composition, classification of the mixture and handling precautions.

PDF · 0,2 Mo

Download

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delivery time

Liquid dispatched by tracked parcel from France. Exact shipping costs and final delivery times are displayed at checkout once your address has been entered. Outside the European Union, import duties and taxes are the responsibility of the recipient.

Frequently asked questions

6 questions

6 key questions

Can it be used in aquaponics?

Yes, on a fish-free system or a decoupled loop, where it is used as in hydroponics, at 2 ml per litre.

On a stocked pond, the hydroponic dose would introduce around 0.2 mg of copper per litre — a level that fish tolerate poorly.

In that case, correct iron alone with a DTPA chelated iron, or significantly reduce the dose while monitoring your fish and the copper level with a drop-based copper test kit.

What trace elements does it contain?

It contains seven, four of which are in chelated form.

Element	Content	Form
Iron	0,1 %	Chelated
Manganese	0,025 %	Chelated
Zinc and copper	0,01 %	Chelated
Boron	0,01 %	Boric acid
Molybdenum	0,003 %	Molybdate
Cobalt	0,001 %	Soluble

What dose for a 50-litre reservoir?

Should it be added to a TriPart fertiliser?

How should it be applied as a foliar spray?

Is it suitable for organic farming?

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Chelated liquid trace elements for hydroponics

The summary