Box of the copper Cu water test in drops, labelled 50 X TEST, on a white background

Copper kit contents: grey colour comparator block, syringe, two glass test tubes, two reagent bottles and colour chart

$Diagram showing the fate of copper in a tank: dissolved fraction measured, insoluble compounds deposited on the bottom$

Copper Cu water test in drops

Name: Copper Cu water test in drops
Brand: Hardy Dewerse
SKU: J2411400
Price: 3000.0 JPY
Availability: InStock

¥3,000

¥1,000 × 3 with no fees Klarna.

Copper is tested to confirm it is absent from the water: at doses a fish can tolerate, it kills your shrimps, snails, and freshwater shrimps.

This test measures dissolved copper in fresh water, ponds, and salt water, using a colour comparator block that cancels out the natural tint of your water.

Ref. J2411400·Water test

Customer support 7 days a week by email

Delivery within 2 to 15 business days

100 % secure payment

The summary

What you receive: 2 bottles of reagents, 2 glass test tubes with screw caps, a syringe, a grey comparator block and a colour chart.
What you measure: dissolved copper in the water, in freshwater aquariums, marine tanks and garden ponds.
What the figure means: a level that a fish tolerates during a treatment is enough to kill a shrimp or a snail.
When to use it: before introducing invertebrates, after a treatment, or on water taken from an old setup.
How to choose: copper is only included in the more comprehensive of the two kits.
What is sent to you: a 0.15 kg parcel, with the reagents in their original box.

Drop test for dissolved copper, 50 measurements, for shrimps, snails and fish

Copper is a trace element needed by every living cell and a cellular poison beyond a certain concentration. Its particular feature is its selectivity: copper-based antiparasitic treatments work precisely because the concentrations aimed for are tolerated for a time by fish while parasites cannot withstand them. What holds for a parasite also holds for a shrimp, a snail and a gammarus. If your invertebrates disappear while your fish stay in perfect health, you have good reason to look here before looking elsewhere.

🚰 Where the copper comes from

Few fishkeepers add copper deliberately, and yet it gets in by four routes, three of which go unnoticed. Identifying the source lets you remove it, and testing then confirms that the input has really stopped, since a single reading says nothing about a source that keeps feeding the tank between two tests. So go through these four entry points at the same time as you take your first reading.

Treatments from the pet shop

Many antiparasitic treatments and some algae treatments contain it, and this can only be seen in the composition.

Copper pipes

When water stands in copper pipes, significant amounts leach out of them. Flush the pipes before filling.

Inputs for the plants

Several aquatic fertilisers contain it as a trace element. It has no effect on fish, but should be watched in a shrimp tank.

Rainwater from the gutter

A copper gutter is enough to contaminate collected water. This water is not suitable for an invertebrate tank.

🧫 Dissolved copper and bound copper

This test measures dissolved copper, and only that, whereas copper quickly forms insoluble compounds that settle on the bottom. Part of what was added therefore leaves the water column within a few hours and binds to the grow medium, the filter media, the decorations and the organic debris on the bottom, where the measurement can no longer detect it. In a treated body of water, most of the copper added ends up in the sediment within a few days. The copper does not break down for all that: it simply moves from the water column to the sediment, from where it can be released again when the pH drops or the substrate is disturbed.

Compliant drinking water and invertebrates

Perfectly compliant tap water can contain up to 2 mg/L of copper, since that is the European regulatory limit. Yet the value that protects 95% of freshwater species is 0.0014 mg/L, a factor of a thousand lower. Compliant drinking water can therefore remain toxic to invertebrates, and only a measurement reveals it.

Remove residual copper after a treatment

Once the treatment is finished, the fraction still dissolved continues to weigh on the invertebrates you will want to reintroduce. Activated carbon adsorbs it within a few days, which no partial water change does as completely, and it removes the residues of the active molecule along the way. Place it in the filter as soon as the treatment ends, then test again before putting back a single shrimp. One litre is enough for a tank of ordinary size and should be replaced after each use.

🧪 When to use this test

Three situations justify getting it out, and outside of these you can leave it in its drawer. The first is a loss of invertebrates in your tank with no mortality among the fish, which is the most common signature. The second is monitoring a treatment in progress, where the measurement is used to check that the concentration stays within the useful range. The third is a doubt about the top-up water, whether it comes from your older copper plumbing or from a gutter collection system. In this respect the test is similar to the iron test: a metal is measured when there is a reason to, not every week.

🪸 Treating without condemning the tank

A tank that has received a copper treatment does not become a shrimp tank again with a simple water change, because the insoluble compounds remain in the substrate. They can only be removed by discarding the substrate completely, which amounts to setting the tank up again. So treat in a hospital tank whenever possible, or consider the substrate lost before you even pour the first dose. This is a decision to make before the treatment, never after. Our articles on choosing a fertiliser and on green pond water look again at the two situations where the question arises most often.

Technical specifications

The essentials

Parameter measured: Dissolved copper in the waterCopper already bound to the substrate, decorations or filter media is not counted
Recommended level: Less than 0.05 mg/LOutside of treatment, in freshwater or marine aquariums as well as ponds
Tests per kit: Approximately 50
Method: Two samples in the comparator blockOne treated and one control, which cancels out the natural tint of your water, even if it is amber
When to use it: Filling, mortality, dosing a treatmentPlus any water drawn from an old setup
Manufacturer's reference: JBL 2411400, PROAQUATEST range

The procedure

Water volume: 2 times 5 mlOne treated sample and one untreated control, drawn with the syringe supplied
The steps: Rinse, fill, add reagent 1, add reagent 2, wait, read5 drops of each reagent in the treated test tube only
Waiting time: 15 minutesUntil the colour has fully developed. Reading it early will underestimate the actual concentration
Total duration: Around 17 minutesWaiting time included
Reading: In daylight, inside the blockNever under the tank lighting, whose tint distorts the comparison
Environments covered: Freshwater, pond, seawaterSalt dampens the reaction, so the marine scale is separate

Security and parcels

Ranking: WarningThe lower of the two threshold levels under CLP regulations
Main risks: Flammable, causes serious eye irritationHazard statements H226 and H319. Only reagent 2 is classified, reagent 1 is not
Precautions: Rinse the eye with water, keep out of reachStatements P101, P102, P305 with P351 and P338, and P501a for disposal
Parcel weight: 0.15 kgPackaging included

To budget for separately

Reagent refill: Reagents only, ref. 2411500The glassware, comparator block and colour chart can be kept
Enough to remove the copper: Activated filtration carbonIt picks up dissolved copper, not copper already bound to the grow medium

10 further specifications are available in the detailed view.

In the box

2 reagent bottles
2 glass test tubes with screw caps
1 graduated sampling syringe
1 grey comparator block with reading slot
1 colour chart and 1 multilingual instruction leaflet, French included

Reference, EAN code, number of measures, kit contents, protocol, use cases and hazard statements taken from the manufacturer's data sheet and instructions on 05/09/2026. Recommended level: JBL brochure for the PROAQUATEST tests. The limit of 2 mg/L in drinking water is the European regulatory value, and the value of 0.0014 mg/L is a guideline value for protecting freshwater species.

Just one metal, or all of the water chemistry?

Copper is missing from entry-level kits. That is the main reason to buy this test on its own, and the only question to settle is what you will actually be measuring.

What cures a fish will sterilise a shrimp tank A few hundredths of a milligram per litre are enough to kill shrimp and snails. Copper arrives through a treatment, through an old water pipe, or through a borehole.

	Parameters covered (parameters)	Drop tests included (tests)	Copper Cu	pH, KH, nitrite, nitrate, ammonium	GH, iron, phosphates, oxygen, silicates	Reagent bottles (bottles)	Glass test tubes	Laboratory comparator block	Thermometer	Reagent refill sold separately	Price
Recommended Copper test onlyYour choice	1 parameters	1 tests	Yes	No	No	2 bottles	2	Yes	No	Yes	¥3,000
6-in-1 Aquarium Water Testing KitYour choice	6 parameters	5 tests	No	Yes	No	9 bottles	3	Yes	No	Yes	¥9,300
13-in-1 water testing kit for aquariumsYour choice	12 parameters	13 tests	Yes	Yes	Yes	23 bottles	12	Yes	Yes	Yes	¥21,700

Copper test onlyRecommended

What you're measuring

Parameters covered (parameters)1 parameters

Drop tests included (tests)1 tests

Copper CuYes

pH, KH, nitrite, nitrate, ammoniumNo

GH, iron, phosphates, oxygen, silicatesNo

Equipment supplied

Reagent bottles (bottles)2 bottles

Glass test tubes2

Laboratory comparator blockYes

ThermometerNo

Budget

Reagent refill sold separatelyYes

6-in-1 Aquarium Water Testing Kit

What you're measuring

Parameters covered (parameters)6 parameters

Drop tests included (tests)5 tests

Copper CuNo

pH, KH, nitrite, nitrate, ammoniumYes

GH, iron, phosphates, oxygen, silicatesNo

Equipment supplied

Reagent bottles (bottles)9 bottles

Glass test tubes3

Laboratory comparator blockYes

ThermometerNo

Budget

Reagent refill sold separatelyYes

13-in-1 water testing kit for aquariums

What you're measuring

Parameters covered (parameters)12 parameters

Drop tests included (tests)13 tests

Copper CuYes

pH, KH, nitrite, nitrate, ammoniumYes

GH, iron, phosphates, oxygen, silicatesYes

Equipment supplied

Reagent bottles (bottles)23 bottles

Glass test tubes12

Laboratory comparator blockYes

ThermometerYes

Budget

Reagent refill sold separatelyYes

Parameters covered, equipment supplied and kit contents noted from the three product pages on 05/09/2026.

Documents & manuals

Official manufacturer's instructions, in French

Complete six-step protocol, the source of copper in tap water, and the instruction explaining how to remove insoluble compounds.

PDF · 1,6 Mo

Download

Estimate your
delivery time

0.12 kg parcel, dispatched within 48 hours by Colissimo or Chronopost home delivery, to be chosen at checkout. The reagents ship in their original box. The exact cost is shown in the basket.

Frequently asked questions

8 questions

6 key questions, 8 in the detailed view

My shrimp are dying and my fish are perfectly fine, is it the copper?

My plumbing is copper, should I be worried?

Does a test reading of zero prove there is no copper?

How do I remove copper from a treated tank?

Remove the surviving invertebrates to an unaffected tank.
Run the water over activated carbon, which captures the dissolved fraction.
Change part of the water, several times rather than in one large change.
For the bound fraction, there is no other way than to throw away the grow medium.

This is why a copper treatment is done in a hospital tank whenever possible: the decision is made beforehand, not afterwards.

Which values should you remember?

Why read it in daylight and not in front of the tank?

Is the test suitable for seawater?

How often does it need to be done?

Let us talk about your project

A question about this product or your setup? Our team will answer and advise you.

Email us Contact form

Interest-free instalment payments

Offered depending on the cart amount, at checkout.

Delivery in 2 to 15 working days

Depending on the products and shipping sites. Estimate by destination in the estimator on this page.

After-sales service 7 days a week by email or chat

Our team answers all your questions.

Shop responsibly

Become part of the change.

Copper Cu water test in drops

The summary