Cardboard box for the iron Fe drop test, labelled 50 tests, for aquarium, pond and saltwater

Contents of the iron test kit: grey comparator block, two glass test tubes, syringe, reagent bottle, and colour chart

Colour chart for the iron test placed under the comparator block and its two test tubes, nine colour fields from 0.02 to 1.5 mg per litre

Adding the five drops of reagent to the test tube placed in the comparator block, above the colour chart

Drop-bottle of iron Fe reagent, white cap, alone on a white background

Iron (Fe) water test, drop format

Name: Iron (Fe) water test, drop format
Brand: JBL
SKU: J2411600
Price: 69.0 AED
Availability: InStock

Dhs. 69.00

Dhs. 23.00 × 3 with no fees Klarna.

Iron is one of the first elements to run short in an aquaponic system, and its deficiency shows in the foliage. This test gives the truly dissolved iron, from 0.02 to 1.5 mg/L, in 12 minutes.

One measurement a week after filling is enough as a routine. Around an addition, one measurement just beforehand and another 24 to 48 hours afterwards show you what your system really consumes.

Ref. J2411600·Water test

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The summary

What you receive: one bottle of reagent, two glass test tubes, a syringe, a grey comparator block and the colour chart, for around 50 measurements.
What you read: dissolved iron, from 0.02 to 1.5 mg/L, across nine colour fields, in freshwater, in a pond and in seawater.
What level to aim for: 0.1 to 0.2 mg/L in a planted aquarium, around 2 mg/L for the crops of an aquaponic system according to the FAO, and no more than 0.05 mg/L in seawater.
When to measure: just before a dose, then one to two days afterwards. With two readings you know your actual consumption.
How to choose: iron is included in the 13-in-1 case and in the iron version of the 6-in-1 case.
Handling: the Fe reagent may cause an allergic skin reaction; the test is carried out away from the tank, and nothing from the test tube ever goes back into the fish's water.

Drop test for dissolved iron, from 0.02 to 1.5 mg/L, for managing chelate dosing

This drop test measures dissolved iron from 0.02 to 1.5 mg/L, for about 50 measurements, and tells you whether your crops need a chelate supplement. Draw the water into the test tube, away from the tank: the reagent never goes into the fish's water. The Fe refill restocks the same kit.

In aquaponics, fish feed provides very little iron, which makes it the most common deficiency in growing beds. It can be spotted by eye well before it is measured, provided you look at the right part of the plant, because three other deficiencies produce similar yellow foliage. This test measures the truly dissolved iron in your system's water and lets you settle the question.

🍃 Where the yellowing begins

Iron is among the least mobile elements in the plant. Once fixed in a leaf, it is not redistributed to the younger organs, so the deficiency appears on the top leaves, where the blade turns pale between veins that stay green. The first leaves, at the base of the stem, can meanwhile stay perfectly green for several weeks. By contrast, nitrogen and magnesium circulate in the sap and are moved to the new growth, so their deficiency begins at the bottom of the plant. Observing where the yellowing starts therefore remains the only reliable way to sort the causes before any measurement, and the guide to iron deficiency in aquaponics covers it species by species.

🧲 Precipitation and chelate form

One chemical constraint remains, and it dictates the choice of product. In well-aerated water, iron that has not been chelated does not stay in solution: above pH 6.5 it oxidises and precipitates within a few hours. An aquaponic system combines precisely these two conditions, since it has highly oxygenated water and a pH that most often stays above 6.5. A reading of zero the day after an application therefore points to precipitation rather than uptake by the plants, and the distinction completely changes the correction you need to make. This is why iron is sold in chelated form, a complexing molecule that keeps it dissolved; and as each chelating agent has a limit pH beyond which it releases the iron, the form should be chosen according to the pH of your water rather than the measured content.

EDTA 13%

The pH limits it at the low end. Reserved for acidic water, it releases iron as soon as the pH rises.

DTPA 11%

The usual compromise, stable up to neutral to slightly alkaline water.

EDDHA 6%

Highest limit pH, for hard water. It turns the water red.

Initial measurement

Measure the pH of your water before buying the chelate, since it is the pH that determines the form.

The ammonium reagent skews the iron reading

A trace of reagent from the ammonium test left in a test tube raises the iron value read, and it is by far the main cause of an abnormally high result. Rinse your test tubes three times with the water to be analysed before each measurement, and avoid using the same glassware for both tests without this rinsing. Dedicated glassware for each parameter remains the safest solution as soon as you monitor several values.

Choose the chelate form before the dose

The pH determines whether an iron supplement will stay available or precipitate, which makes it the measurement to take before you even place an order. The liquid pH test is done on the same sample as this one. Above pH 7, the 6% EDDHA chelate stays stable where an EDTA has already released its iron, whereas between 6 and 7 the 11% DTPA is enough and does not colour the water. Choosing the form according to the pH, rather than at random from the shelf, avoids repeated applications with no visible change in the foliage.

🧪 Bracketing a dose with two measurements

Unlike nitrates, whose concentration rises on its own as long as the fish are being fed, the iron level depends entirely on what you add. It rises after each addition, then falls as the plants absorb it and some of it precipitates. A single measurement therefore tells you little, whereas by bracketing the addition with two tests, one just before and the other 24 to 48 hours afterwards, you directly obtain the proportion of iron that has remained available. The speed at which the value drops over the following days then gives you the interval to leave between two additions. Both of these benchmarks depend on the pH of your water, the cultivated area and the species in place, so no general dosage can replace them.

🌿 When iron is sufficient

A normal reading is as useful as a low one, since it rules out iron and sends you looking elsewhere. Two causes dominate when the level is adequate and the young leaves stay pale. A high pH blocks uptake well before the element disappears from the water, and a manganese deficiency produces a very similar leaf pattern. If, on the other hand, the yellowing starts at the bottom of the plant, the measurement to take is that of magnesium or potassium, and the guide to deficiencies in aquaponics presents these patterns side by side.

🧤 Handling the Fe reagent

The reagent in this test contains ammonium thioglycolate, a sulphur compound classified as harmful if swallowed, irritating to the eyes and capable of causing an allergic skin reaction on sensitive skin. It therefore never leaves the test tube: you take the tank water into it, count the drops, read the shade, then tip the sample down the sink before rinsing the glass with clean water. A sample poured back into the tank would bring this reagent to the fish and, in an aquaponic system, to the roots that the same water then irrigates. If your skin reacts easily, thin gloves are enough, and the bottle is stored recapped, out of reach of children, together with the Fe reagent refill for when the first bottle runs out.

Technical specifications

Measuring dissolved iron

Parameter measured: Dissolved iron, in mg/LThe reaction colours the iron that has remained in solution; whatever has precipitated to the bottom of the tank is not counted
Colour chart range: 0.02 to 1.5 mg/LFirst field marked below 0.02, last field 1.5
The colour fields: 0,02 ; 0,05 ; 0,1 ; 0,2 ; 0,4 ; 0,6 ; 0,8 ; 1,0 ; 1,5Nine steps, tightened at the low end of the scale where the decision to add is made
Target values: 0.1 to 0.2 mg/L in a planted aquariumAround 2 mg/L in aquaponics, read on a sample diluted by half. Up to 0.6 mg/L in a heavily planted tank, 0.05 mg/L at most in seawater
Tests per kit: Around 50A single bottle of reagent, 5 drops per measurement
Manufacturer's reference: JBL 2411600, PROAQUATEST rangeNot to be confused with the refill, reference 2411700

The procedure

Sample volume: 2 times 5 mlOne test tube receives the reagent, the other is left as it is and serves as a control
The steps: Rinse, sample, dose, mix, wait, read5 drops from a single bottle, held vertically, with a dry tip and no bubble
Standing time: 10 minutesFull colour development. Reading earlier underestimates the value
Total time: About 12 minutesRinsing and reading included
Reading: In the notch of the comparator blockThe block slides along the colour chart until the two shades match
A pitfall to know about: Rinse beforehand, several timesTraces of ammonium reagent in the test tube give a falsely high iron reading

Hazard labelling

Signal word: WarningThe Fe reagent is the only bottle in the kit
Pictogram: Exclamation mark, GHS07Acute toxicity, sensitisation and irritation
Hazard statements: H302, H317, H319Harmful if swallowed, may cause an allergic skin reaction, causes serious eye irritation
Precautionary statements: P101, P102, P303+P361+P353, P305+P351+P338, P501Label to show the doctor, keep out of reach of children, rinse skin and eyes, dispose of according to local rules
Storage: Dry, at room temperatureIn the original packaging, away from direct light
Tested sample: Poured down the sinkNever poured back into the tank or into the fish circuit

To allow for in addition

The iron to be measured: A chelate suited to your pHEDTA in acidic water, DTPA in neutral water, EDDHA in hard water
Reagent refill: Reagent only, ref. 2411700Test tubes, syringe, block and colour chart stay in use

12 further specifications are available in the detailed view.

In the box

1 dropper bottle of Fe reagent
2 glass test tubes with screw caps
1 graduated syringe for drawing up 5 ml
1 grey comparator block with two slots
1 nine-field colour chart, from 0.02 to 1.5 mg/L
1 multilingual leaflet with the protocol in French

Manufacturer's values (instructions, colour chart and safety data sheet for the Fe reagent). Aquaponic reference value taken from the FAO guide.

Manufacturer and product safety

Manufacturer: JBL GmbH & Co. KG
Postal address: Dieselstraße 3, 67141 Neuhofen, Allemagne
Contact: info@jbl.de
Website: www.jbl.de

Information provided under Regulation (EU) 2023/988 on general product safety.

The iron test on its own, or a case that includes it

Iron is included in the 13-in-1 kit and in the iron version of the 6-in-1, with the 6-in-1 column here describing its ammonium version.

Iron chlorosis starts with the young leaves Iron does not move within the plant: the deficiency affects new growth and leaves the veins green. If your older leaves are turning yellow, look instead to nitrogen.

	Parameters covered	Drop test kits included	Iron Fe	pH, KH, nitrite and nitrate	GH, phosphates, copper, silicates, oxygen	Reagent bottles	Glass test tubes	Laboratory comparator block	Thermometer	Reagent refill sold separately	Price
Recommended Iron test onlyYour choice	1	1	Yes	No	No	1	2	Yes	No	Yes	Dhs. 69.00
6-in-1 Aquarium Water Testing KitYour choice	6	5	No	Yes	No	9	3	Yes	No	Yes	Dhs. 213.00
JBL ProAquaTest Lab water analysis case, 13 tests for aquarium and pondYour choice	12	13	Yes	Yes	Yes	23	12	Yes	Yes	Yes	Dhs. 417.00

Iron test onlyRecommended

What you are measuring

Parameters covered1

Drop test kits included1

Iron FeYes

pH, KH, nitrite and nitrateNo

GH, phosphates, copper, silicates, oxygenNo

Equipment supplied

Reagent bottles1

Glass test tubes2

Laboratory comparator blockYes

ThermometerNo

Budget

Reagent refill sold separatelyYes

6-in-1 Aquarium Water Testing Kit

What you are measuring

Parameters covered6

Drop test kits included5

Iron FeNo

pH, KH, nitrite and nitrateYes

GH, phosphates, copper, silicates, oxygenNo

Equipment supplied

Reagent bottles9

Glass test tubes3

Laboratory comparator blockYes

ThermometerNo

Budget

Reagent refill sold separatelyYes

JBL ProAquaTest Lab water analysis case, 13 tests for aquarium and pond

What you are measuring

Parameters covered12

Drop test kits included13

Iron FeYes

pH, KH, nitrite and nitrateYes

GH, phosphates, copper, silicates, oxygenYes

Equipment supplied

Reagent bottles23

Glass test tubes12

Laboratory comparator blockYes

ThermometerYes

Budget

Reagent refill sold separatelyYes

Contents of the three kits taken from their respective product pages.

Documents & manuals

Official manufacturer's instructions, French section

The full six-step protocol, the reference volume of 2 times 5 ml, the 5 drops of reagent, the 10 minutes' standing time, and the warning about test tubes shared with the ammonium test.

PDF · 2,9 Mo

Download

Estimate your
delivery time

Parcel of 0.13 kg, dispatched within 48 hours by Colissimo or Chronopost home delivery, as you choose at checkout. The reagent bottle is sent in its original cardboard box, with the glassware wedged in place. The exact shipping cost is shown in your basket. Once unsealed, this product cannot be returned under the right of withdrawal (article L221-28, 5° of the French Consumer Code), for reasons of hygiene and health protection.

Frequently asked questions

8 questions

6 key questions, 8 in the detailed view

What iron level should you aim for in the water?

My test shows 0 just after an addition, is that normal?

Yes, and it is actually the most common case. Bare iron oxidises and precipitates within a few hours once the pH rises above 6.5 in well-oxygenated water. A zero reading the next day therefore means the iron has dropped out of solution, not that your plants have used it all.

This is the whole point of chelates: the molecule wrapped around the iron keeps it dissolved, and each chelating agent has a pH ceiling beyond which it releases the iron. If you keep getting zero readings despite a chelated supplement, change the form of chelate rather than the dose.

Why do two iron tests not give the same figure?

The colour matches none of the squares on the colour chart, what has happened?

Should you measure pH as well as iron?

Is the iron reagent dangerous for my fish?

It must never enter the fish water, and the method is designed with that in mind. You draw 5 ml into the test tube, dose it into the vial, then pour the coloured sample down the sink.

Never pour a tested sample back into the tank: in aquaponics, the same water then passes through the roots of your crops.

Before this test, rinse the test tube several times if it has been used for the ammonium test: traces of its reagent will skew the iron reading upwards.

How often should I measure?

Can the reagent trigger a skin allergy?

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Iron (Fe) water test, drop format

The summary