JBL ProAquaTest CombiSet Plus NH4 test kit case, closed, with the pH, KH, NO2, NO3, CO2 and NH4 parameters shown on the front

JBL ProAquaTest CombiSet Plus Fe test case closed, with the pH, KH, NO2, NO3, CO2 and Fe parameters on the front

JBL ProAquaTest CombiSet case open: reagent bottles, test tubes, syringe, colour comparator block, and colour charts

CombiSet Plus Fe test case open: seven reagent bottles, syringe, test tubes, measuring spoon and comparator block

Interior of a JBL ProAquaTest kit case viewed close up, reagent bottles, test tubes and measuring syringe

Measuring ammonium with a JBL ProAquaTest kit, test tubes placed on the colour chart alongside the reagent bottles

JBL ProAquaTest CombiSet colour comparator chart – nitrogen cycle parameter readings for aquariums

6-in-1 Aquarium Water Testing Kit

Name: 6-in-1 Aquarium Water Testing Kit
Brand: JBL
SKU: J2409000
Price: 50.9 EUR
Availability: InStock

50,90 €

16,96 € × 3 with no fees Klarna.

This case brings together five drop tests to read pH, KH, nitrite, nitrate and, depending on the version, ammonium or iron. A table also gives CO2, and the reagents, glassware, syringe, comparator block and colour charts are all in the case.

The ammonium version tracks a start-up day by day, while the iron version monitors plant nutrition in an established tank or an aquaponic system.

Ref. J2409000·Water test

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Avec fer Fe

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The summary

What you receive: a case of 5 drop tests, 9 bottles in the ammonium version or 7 in the iron version, 3 glass test tubes, a syringe and a comparator block.
What you measure: pH, KH, nitrite, nitrate, and ammonium or iron depending on the version, plus CO2 read from a chart.
How long it takes: 2 minutes for KH, 12 minutes for iron, 17 minutes for ammonium, waiting time included.
Which version: ammonium for a new set-up, iron for an established tank or an aquaponic system where the crops matter.
What runs out: the bottles only. The glassware, syringe, comparator block and colour charts stay.
What is sent to you: the case sealed, with the reagents in their original compartments.

JBL case of 5 drop tests: pH, KH, nitrogen, and either ammonium or iron

The JBL 6-in-1 water test case is used to monitor the water in an aquarium, a pond or an aquaponic system. Five drop tests measure pH, KH, nitrite, nitrate and either ammonium or iron, depending on the version, while a chart gives the CO2 level. Ammonium suits a new set-up, iron a well-established tank.

Clear water can contain toxic amounts of ammonium and nitrite. Between the moment ammonium starts to build up and the moment the fish gather at the surface, several days pass during which nothing is visible. This kit gives you the five measurements that make those days readable, with drop-bottle reagents and a laboratory comparator block.

🧪 The six parameters in the kit

Five drop tests cover pH, KH, nitrite, nitrate and, depending on the version, ammonium or iron. The sixth parameter, carbon dioxide, uses no reagent, since it is read from a chart that cross-references the pH and KH you have just measured. The ammonium version has 9 bottles: three for ammonium, two for nitrite, two for nitrate, one for pH and one for KH. The iron version has 7, since iron is measured with a single reagent. Ammonium, nitrite and nitrate are enough to follow the nitrogen cycle from the first day until it stabilises.

🕒 How a session unfolds

Sampling

Fill the test tube from the middle of the tank, never at the surface or against the sand. Rinse it first with tank water.

Dose

Count the drops on 5 ml of water, 10 ml for nitrate, shaking after each reagent is added.

Wait

The KH changes colour immediately, the pH and nitrite take 5 minutes, the nitrate and iron 10, the ammonium 15.

Read

Place the test tube in the comparator block and read the tint against the colour chart, in daylight.

Three habits that skew the reading

Rinsing glassware with tap water leaves traces that skew the readings for a long time, whereas rinsing with tank water costs nothing. Laying a dropper bottle on its side lets air in and gives uneven drops, and therefore a wrong KH titration: hold the nozzle vertically downwards. Finally, reading a colour under a warm bulb distorts how the shades look, which mainly affects the pinks of the nitrite and nitrate tests. Several reagents are classified as hazardous: those for KH, nitrite and nitrate cause severe skin burns and eye damage (H314, H318), and ammonium reagent 3, in the ammonium version, is highly flammable (H225). Work over a sink, wearing gloves and well away from any flame.

The refills that go first

Nitrite and ammonium are the two tests whose bottles you will empty during start-up, because they are the ones you use every day. The nitrite reagent refill and the ammonium refill use exactly the same bottles, without the glassware or colour charts that you keep. Order them together if you are starting a new tank, and you will not run short in the week when measuring matters most.

The ammonium version covers the nitrogen cycle and the acid-base basics, that is, the values on which your fish depend first. The iron version replaces ammonium with iron, the test that explains foliage turning yellow between veins that have stayed green: it suits an established tank, where ammonium no longer needs measuring every day, and an aquaponic system where the crops matter as much as the fish. Phosphate and total hardness belong to a broader monitoring routine, which the 13-in-1 test case brings together in a single kit.

🌱 Nitrogen and iron in aquaponics

In aquaponics, these values are not read the way they are in an aquarium. Nitrate becomes a resource here, since it feeds your lettuces, whereas an aquarist is trying to bring it down. Ammonium and nitrite remain the two figures to monitor every day until the biofilter has established, and the KH tells you whether your pH will hold through the week. That is why starting up a system calls for daily measurements over 3 weeks. Once the system has settled in, iron takes over, because it is the element most often lacking in the crops: iron deficiency shows up on the test before it shows on the leaves.

🔁 How often to harvest

The routine changes with the age of the installation. During the first 3 weeks, a daily reading of ammonium and nitrite is justified, as these are the two compounds that are toxic to fish even at low concentrations. Once the cycle is established, a weekly reading of the five parameters is enough, and a monthly reading will do for a stable, lightly stocked tank. Go back to the daily routine, however, after a medicinal treatment, a filter clean or the arrival of new fish, since these events reduce the bacterial population or suddenly increase the nitrogen load.

Technical specifications

The essentials

Parameters measured: pH, KH, NO2, NO3, CO2, and NH4 or FeCO2 uses no reagent; it is read from a table cross-referencing pH and KH
Drop tests included: 5, i.e. 9 or 7 bottles9 bottles in the ammonium version, three of them for ammonium; 7 in the iron version, as iron needs only one reagent
Method: Liquid reagents, colorimetric readingThe supplied comparator block cancels out the water's own tint when you take the reading
Environments covered: Freshwater, pond, aquaponicsThe colour charts carry a freshwater band, a pond band and a seawater band
Dimensions of the box: 26.6 x 22.6 x 5.2 cm
Bottle safety: Child-resistant capsThe case itself is water-resistant

The five tests, one by one

pH: Wide range, 3.0 to 10.0It gives you a rough idea of an unknown water. Adjusting to the tenth needs a fine range
KH, carbonate hardness: Titration, 1 drop = 1 °dKHOn 5 ml of water. There is no colour chart for this test, you count the drops until the colour changes
NH4 or Fe, depending on the version: 3 reagents for NH4, 1 for FeIron reads from 0.02 to 1.5 mg/L. The toxic share of ammonia is worked out from a table crossing pH and temperature
NO2, nitrites: Colorimetric, 2 reagentsOn 5 ml of water, read after 5 minutes. This is the reference test during cycling
NO3, nitrates: Colorimetric, 2 reagentsPer 10 ml of water. In aquaponics, this is the nitrogen ration for the crops
CO2, carbon dioxide: No reagent, read off the chartThe value is read by cross-referencing the pH and KH already measured

The procedure

Water volume per test: 5 or 10 ml5 ml for pH, KH, nitrite, ammonium and iron, 10 ml for nitrate
Waiting time: 0 to 15 minutesNone for KH, 5 minutes for pH and nitrite, 10 for nitrate and iron, 15 for ammonium
The steps: Rinse, fill, dose, shake, wait, readIn this order. Insufficient shaking after each reagent gives a shade that is too pale
Reading: Colour chart, in daylightA warm artificial light shifts the perception of pink and orange shades

To budget for separately

Reagent refills: Sold test by testThe glassware, syringe, measuring scoop, comparator block and colour charts are kept
Phosphates, ammonium or iron: Phosphate test, iron or ammoniumThe test that your version does not include, and phosphate, useful as soon as you grow fruiting plants

10 further specifications are available in the detailed view.

In the box

1 water-resistant plastic case
5 drop tests with child-resistant caps
3 graduated glass test tubes
1 plastic test tube
1 sampling syringe
1 scoop for the powdered reagent
1 laboratory comparator block
1 set of colour charts
1 CO2 conversion chart, with pH and KH entries
1 set of analysis record sheets
9 reagent bottles in the ammonium version, or 7 in the iron version

Parameters, equipment and case dimensions taken from the official JBL PROAQUATEST data sheets on 10/09/2026, iron version taken on 11/10/2026. The count of 6 parameters adds CO2 to the 5 tests, read from the chart supplied.

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.

Ammonium, iron, or 13 tests?

The three kits use the same drop reagents and the same comparator block. What sets them apart is the parameter you monitor on top of the basics, and the space they take up.

A common base, with one parameter that changes Both versions of the 6-in-1 case give pH, KH, nitrite, nitrate and CO2, then either ammonium or iron. Two answers are enough to decide.

	Parameters covered (parameters)	Drop tests included (tests)	Reagent bottles (bottles)	pH, KH, nitrite, nitrate and CO2 by table	Ammonium NH4	Iron Fe	GH, phosphates, dissolved oxygen	Glass test tubes	Laboratory comparator block	Thermometer	Format	Price
Recommended With ammonium NH4Your choice	6 parameters	5 tests	9 bottles	Yes	Yes	No	No	3	Yes	No	Compact case	50,90 €
With iron FeYour choice	6 parameters	5 tests	7 bottles	Yes	No	Yes	No	3	Yes	No	Compact case	46,90 €
13-in-1 water testing kit for aquariumsYour choice	12 parameters	13 tests	23 bottles	Yes	Yes	Yes	Yes	12	Yes	Yes	Complete laboratory	99,90 €

With ammonium NH4Recommended

What each kit measures

Parameters covered (parameters)6 parameters

Drop tests included (tests)5 tests

Reagent bottles (bottles)9 bottles

pH, KH, nitrite, nitrate and CO2 by tableYes

Ammonium NH4Yes

Iron FeNo

GH, phosphates, dissolved oxygenNo

Equipment supplied

Glass test tubes3

Laboratory comparator blockYes

ThermometerNo

FormatCompact case

Price

With iron Fe

What each kit measures

Parameters covered (parameters)6 parameters

Drop tests included (tests)5 tests

Reagent bottles (bottles)7 bottles

pH, KH, nitrite, nitrate and CO2 by tableYes

Ammonium NH4No

Iron FeYes

GH, phosphates, dissolved oxygenNo

Equipment supplied

Glass test tubes3

Laboratory comparator blockYes

ThermometerNo

FormatCompact case

Price

13-in-1 water testing kit for aquariums

What each kit measures

Parameters covered (parameters)12 parameters

Drop tests included (tests)13 tests

Reagent bottles (bottles)23 bottles

pH, KH, nitrite, nitrate and CO2 by tableYes

Ammonium NH4Yes

Iron FeYes

GH, phosphates, dissolved oxygenYes

Equipment supplied

Glass test tubes12

Laboratory comparator blockYes

ThermometerYes

FormatComplete laboratory

Price

Parameters covered and equipment supplied recorded from the official JBL product pages on 10/09/2026, iron version on 11/10/2026.

Estimate your
delivery time

Kit dispatched sealed within 48 hours, reagents in their original compartments, by Colissimo or Chronopost home delivery, as you choose at checkout. The exact cost is shown in your basket once you have entered your address. 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

Which tests are included in the kit?

Ammonium version or iron version: which one should you choose?

The ammonium version is the right choice if you are starting up a tank or a system, or if you add fish often: it shows the first toxic peak of cycling, before nitrite appears.

The iron version suits an established setup where the plants matter. Iron reads from 0.02 to 1.5 mg/L, and in aquaponics, where the target is around 2 mg/L, the reading is taken on a sample diluted by half.

How often should you test during the first few weeks?

A new tank needs close monitoring at first, then less and less:

For the first 3 weeks, measure ammonium and nitrite once a day, always at the same time.
As soon as nitrite falls back to zero and nitrate rises, move to two measurements a week.
Add pH and KH once a week, as these change slowly.
On an established system, one full set of readings a week is enough.
Return to the daily routine after each addition of fish and after any incident.

The nitrite is not dropping, what should you do?

This is an unavoidable stage of any start-up, and it takes time. Here is what to do:

Stop feeding for two days, because ammonium fuels the chain and keeps the spike going.
Do a partial water change to dilute, without rinsing the filter media.
Check the carbonate hardness: below 5 °dKH, the water loses its buffering capacity and the pH becomes unstable, which slows nitrification.
Test again every day, at the same time, until the nitrite returns to zero.

Why is the pH test read to the nearest half point?

Is a KH below 5 dKH a problem?

Is a nitrate level of 40 mg/L a problem in aquaponics?

No, and that is the big difference from an aquarium. In aquaponics, nitrate is the nitrogen ration for your crops, produced by the bacteria and taken up by the roots, and a value that stays low points to plants absorbing nitrogen well rather than to clean water.

What matters is the trend. A nitrate level that rises week after week means you are feeding more fish than you have plants to absorb. The choice of supplements is made on that reading.

How do I reorder a single reagent?

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6-in-1 Aquarium Water Testing Kit

The summary