JBL PROAQUATEST GH General hardness
Quick test to determine the general hardness in freshwater aquariums & ponds

  • Simple and reliable monitoring of the water values in aquariums/ponds. Determines the ideal general hardness in freshwater aquariums and ponds
  • Colour change test: fill plastic cuvette with sample water, add reagent drop by drop until colour changes from red to green. Number of drops = level of general hardness
  • When to use: for setting up a new aquarium: once a week, afterwards once a month
  • You will find detailed information and troubleshooting tips about water analysis on the JBL website in Essentials/Aquarium or Pond
  • Package contents: 1 GH quick test, incl. one reagent and plastic cuvette. Reagent refill separately available
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Recommended retail price incl. VAT
Available from your specialist dealer.
Dealer close to you
You can find this article at your specialist shop and online
Recommended retail price incl. VAT
Available from your specialist dealer.
Dealer close to you
You can find this article at your specialist shop and online
Product information

Healthy aquarium/healthy pond with conditions close to nature
The right water values are dependent on the fish stock and the plants in the aquarium/pond. Even if the water looks clear it can be contaminated. With bad values diseases or algae can appear in the aquarium/pond. To maintain a healthy aquarium/pond with conditions close to nature it is important to check and adapt the water values regularly.

For each water analysis JBL provides water tests in the form of quick tests or colour change tests. These determine a certain value or several values in one go. With these water tests you can recognise algae problems and negative nitrate, nitrite, potassium, magnesium values etc.

Why test?
Depending on origin and consistency of the subsoil, water may contain varying quantities of alkaline earth salts, usually in the form of calcium and magnesium salts. General hardness, by definition, is the sum of calcium and magnesium ions. Most fish and plants thrive well at a general hardness of between roughly 8 and 20°dH. Excessive total hardness values, should, however, be counteracted by the appropriate measures.

JBL Online Laboratory
Regular control for a healthy aquarium/pond with conditions close to nature. Enter your water values into the JBL Online Laboratory and get an in-depth analysis of your values within seconds.

Recommended general hardness values:
Freshwater aquarium (community aquarium): 8-25 °dGH
Lake Malawi/Lake Tanganyika aquarium: 5-20 °dGH
Plant aquarium with few fish (aquascaping): 3-10 °dGH
Marine aquarium: not measurable with GH test because GH too high. Please test calcium and magnesium separately Pond: 6-20 °dGH

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Details

JBL PROAQUATEST GH General hardness

Art. no.:
2410800
EAN Code:
4014162241085
Volume packaging:
0.800 l
Gross weight:
88.500 g
Net weight:
51 g
Weight factor:
0
Packaging dimensions (l/h/w):
43/175/106 mm

Technical Data

Height:175 mm
Length:106 mm
Width:43 mm

JBL PROAQUATEST GH General hardness REFILL

Art. no.:
2410900
EAN Code:
4014162241092
Volume packaging:
0.570 l
Gross weight:
28.000 g
Net weight:
10 g
Weight factor:
0
Packaging dimensions (l/h/w):
30/175/110 mm

Technical Data

Height:64 mm
Length:24 mm
Width:24 mm
diameter:24 mm
FAQ
Where can I find the record sheets for the documentation of my water analysis?

Have you lost your record sheets, used them all up, or need them in another language?
In the appendix of this FAQ you will find PDF files for printing them out in German, English and French.

Why are there no colour charts for GH. KH, Mg /Ca saltwater and CO2 direct?

The tests from the test range: JBL GH test, JBL KH test, JBL calcium test Ca and JBL magnesium test Mg, where the number of drops are counted until the colour changes and the counted value is multiplied by a value:

GH = number of drops = general hardness in °dH

KH = number of drops = carbonate hardness in °dH

CO2 = number of drops * 2 = CO2 in mg/l

Magnesium + calcium = number of drops * 120 = amount Ca + Mg in mg/l

Calcium = number of drops * 20 = amount Ca in mg/l

Magnesium = amount Ca+Mg from magnesium test - amount Ca in mg/l = magnesium in mg/l

I have lost my colour chart. Can I download the colour chart for the test?

The colour cards are not available for download on the JBL website. The absolutely accurate colour reproduction that is required can only be achieved using a printer which can be re-calibrated before each printout. Most privately used printers are not accurate enough for this.

You will find the colour chart bundle as a spare part on the respective product page and in the spare parts shop under: https://www.jbl.de/en/products/detail/8732/jbl-proaquatest-assortiment-color-chart

What can I do when the measured value of a water test falls outside the scale?

If one of your measurements reaches the end of the colour chart scale you can multiply the scale by diluting later tests with distilled water (e.g. JBL Dest).

Here’s how to do it: dilute the sample with distilled water and carry out the test once more.

This works in detail as follows:
GH test: Instead of 5 ml use 10 ml aquarium water. Now 1 drop is equivalent to 0.5 dGH.
KH test: Instead of 5 ml use 10 ml aquarium water. Now 1 drop is equivalent to 0.5 dGH.

Note: when using 10 ml sample water the colour development is weaker with the first drops than with 5 ml sample water. Put the measuring container on a white underlay for a better readability.

NH4/NH3 ammonium/ammonia, NO2 nitrite, Fe iron and Cu copper:
2.5 ml sample + 2.5 ml dist. water: result times 2
1 ml sample + 4 ml dist. water: result times 5
0.5 ml sample + 4.5 ml dist. water: result times 10

NO3 nitrate, SiO2 silicate, PO4 phosphate sensitive and Mg magnesium freshwater:
5 ml sample + 5 ml dist. water: result x 2
2 ml sample + 8 ml dist. water: result x 5
1 ml sample + 9 ml dist. water: result x 10

PO4 phosphate koi high range:
2.5 ml sample + 2.5 ml dist. water: result x 2
1 ml sample + 4 ml dist. water: result x 5

K potassium:
7.5 ml sample + 7.5 ml dist. water: result x 2
3 ml sample + 12 ml dist. water: result x 5
1.5 ml sample + 13.5 ml dist. water: result x 10

K potassium in marine water:
1. Fill 10 ml of sample water with distilled water to 300 ml.
2. Follow the instructions for fresh water.
3. Multiply the test result by a factor of 30.

CO2 direct, Ca calcium and Mg+Ca magnesium+calcium: not required.

Do my water tests still work although they have been open for nine months?

Basically a sealed test keeps longer than an open one. How much the shelf life is reduced depends crucially on the handling and the storage conditions of the reagents. It may happen that a reagent in a test that has been open for 9 months doesn’t indicate correctly any more. However, additional information is needed to answer this question properly.

Blog (opinions & experiences)

JBL TV #11: What is the general hardness? Is the general hardness relevant in the aquarium?

What is the general hardness and how relevant is it in our aquarium?

Find out more

How often do you need to test your pond or aquarium water?

Granted, nobody really enjoys testing water. It’s time-consuming and sometimes you’re not sure which colour on the chart your water result matches. But water testing really can be lifesaving – at least for your fish!

Find out more

Why is the KH higher than the GH?

Many aquarium owners think that the general hardness represents the total of all minerals and the carbonate hardness only a part of it. Then how can the carbonate hardness sometimes be higher than the total of minerals?

Find out more

Testing Water in the Jungle

Our 15 expeditions have taught us something new: In natural waters nitrogens (ammonium/ammonia, nitrite and nitrate) and phosphates are ALWAYS scarce and below the limit of detection. Only when humans have an influence on the natural water, can nitrogens and phosphates be found.

Find out more

Outline: Fertilisation in the Aquarium

The JBL plant care concept leads to vigorous and healthy growth even with the most demanding aquatic plants. JBL has all the components you need, whether it’s a fertiliser, a bottom substrate or a fully automatic CO2 fertiliser system.

Find out more

Care products - The best solutions for your aquarium

With the right products, aquarium care is not only easy, but can also be a lot of fun! The formulas that make up JBL products are based on intensive research and, especially with care products, their effects are not always immediately visible, yet in the medium and long-term they’ll result in a beautiful aquarium and healthy fish.

Find out more

Inaccurate water tests – or did I do something wrong after all?

In the aquarium scene we often hear people talking about “accurate” and “inaccurate” tests. But mostly they mean a rougher or finer scaling of the output values.

Find out more

Testing water – here’s how

The water in your aquarium is outstandingly significant because it is a life-giving element for fish and plants.

Find out more

Keeping an eye on the most important water values

Professional water analysis sounds very expensive. But the professional water testing in your aquarium or pond at home also works on a high level and above all it is simple and inexpensive.

Find out more

Treating fish diseases before they arise

Even if your fish have fallen ill, it is not too late. Nonetheless we want to save the fish from getting ill. About 90 % of all fish diseases are the result of a weakening of the immune system.

Find out more
Press

14.08.2020

JBL has the largest range of water tests worldwide!

With 24 different water analysis tests for freshwater and marine aquariums and ponds as well as 8 different test cases, JBL offers the widest range of water tests worldwide. The second place is shared by two American manufacturers with 15 individual tests each, but with only 0 and 2 test cases respectively.

Find out more

12.03.2019

JBL Water Tests Now Even Better

Scientists, aquarium owners, pond enthusiasts, and especially those who need reliable, accurate water tests, use JBL water tests. Over the years, the JBL development team has been collecting and is now ready to implement your suggestions for improvements.

Find out more
Reference guide (Themeworld)

Testing water

Water can look crystal clear and still contain a deadly poison such as arsenic. Unfortunately we are unable to assess the quality of the pond water by looking at it.

Rainwater

Rainwater gradually softens your pond water. What consequences does this have for your pond?

Seasonal maintenance

Which seasonal maintenance is needed? What do you need to remember when?

The water tests – all parameters

You don't always have to do all the tests, any more than your doctor will look in your ears when your knee hurts. In the following table you will find brief information about where a water test can help.

Algae

Do you have green water or thread algae? We’ll give you long term solutions for algae problems

Diseases

Recognising and treating fish and invertebrate diseases

Deficiency symptoms

Here’s how to prevent deficiency symptoms in fish and plants

Testing water

Testing water – the most important step to understanding your aquarium. Why is water testing necessary?

Fish breeding in aquariums

Would you also like to breed your fish? What do you have to consider when breeding?

Fish species

Which fish species suit your aquarium? What demands do the fish species have?

Invertebrate species

What invertebrate animals are suitable for your aquarium? What demands do invertebrates have? What do you need to consider for their care?

Adding

How to catch fish properly without causing them stress? How to transport and add fish?

Planning and stock

Which fish are compatible? What do you need to consider when selecting fish?

Water tests

What water tests are available? How do water tests work? How do you test properly?

Water values

Which water tests are important? How can you achieve perfect water values?

Plants

Which aquarium plants are best? What’s the best way to plant them?

Biotope (habitat) aquarium types

A real piece of the Amazon or, with the Congo, a piece of the heart of Africa. A habitat (biotope) aquarium is a challenge. Can you emulate nature?

Aquascaping aquarium type JBL Dreamscape®

Mountains, valleys, meadows and fish! Create your dreamlike landscape under water with the Dreamscape® aquarium

Jungle aquarium type JBL Rio Pantanal®

A bit of jungle river in your living room. Lively underwater action! No problem with the JBL Rio Pantanal® aquarium

Goldfish aquarium type JBL Goldfish Paradise®

Lively goldfish in the aquarium enhance any room perfectly! Invite some new flatmates into your home with this goldfish aquarium

Rocky reef aquarium type JBL Malawi Rocks®

The fish of Lake Malawi are as colourful as the fish in the coral reefs. This aquarium brings a bit of freshwater reef into your living room

Fish care

How do you protect your new fish? What to remember when caring for fish?

Daily care

How much daily or weekly care is involved? What are the basic maintenance measures for your aquarium?
Download

Instructions

Additional product information and downloads

safety instructions

spare parts
Safety information
JBL GH - safety information in accordance with GHS
Signal word
Warning
Hazard symbol
  • GHS02
  • GHS07
Risk phrase
H226: Flammable liquid and vapour.
H315: Causes skin irritation.
H319: Causes serious eye irritation.
safety note
P101: If medical advice is needed, have product container or label at hand.
P102: Keep out of reach of children.
P303+P361+P353: IF ON SKIN (or hair): Take off immediately all contaminated clothing. Rinse skin with water [or shower].
P305+P351+P338: IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
P501a: Dispose of contents/container in accordance with local/regional/national/international regulations.

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