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JBL NO3 Nitrate Test Set

by JBL
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SKU J25375
  • Determines optimum nitrate value for ideal plant growth or possible cause of algae in freshwater and marine water.
  • Laboratory comparator system to compensate any inherent water colouring: fill glass vials with sample water, add reagents to another vial, place vials in holder, read values on colour chart.
  • When to use: for setting up a new freshwater aquarium: once a week. For initial setup with marine water: once a week. In case of green algae problems.
  • Online Laboratory: free analysis and recommendations for the water values you have measured.
  • Package contents: 1 quick test, nitrate test NO3. Contents for approx. 50 measurements, incl. 2 reagents, 2 glass vials with screw caps, syringe, dosing spoon, comparator block and colour scale. Reagent refill separately available.


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?

  • Nitrate is the end product of the mineralisation in the aquarium/pond.
  • Even in relatively high concentrations it is non-toxic for fish, but has an adverse effect on plant growth and the well-being of several fish species.
  • Furthermore too high nitrate contents promote unwanted algae growth if phosphate is present in the water as well as nitrate.

Recommended nitrate values:

  • Freshwater aquarium (community aquarium): 0-50 mg/l
  • Lake Malawi/Lake Tanganyika aquarium: 0-50 mg/l
  • Plant aquarium with few fish (aquascaping): 10-30 mg/l
  • Marine aquarium: 0-20 mg/l
  • Pond: 0-10 mg/l.

You can analyse the water values you have measured in the JBL Online Laboratory free of charge and receive recommendations.


Where can I find the record sheets for the documentation of my water analysis?

> Have you lost your record sheets, already filled them all in or do you need them in another language?

With the following links you can quickly and easily print out your new record sheets with recommendations for the individual parameters at home and document the water analyses.

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:

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.

Which of the three scales on the colour cards symbolize of the water tests saltwater, freshwater and garden pond ?

> koi carp = garden pond

angel fish = saltwater

discus = freshwater

Which scale applies for my aquarium? My test has two or three control fields with fish and recommendations.

> We repeatedly receive questions regarding the symbols on the water test. The hobby areas cannot be clearly assigned to the scales for analysis. There are three symbols to make the hobby areas on the colour charts clear:

Discus = fresh water

Emperor = salt water

Koi = garden pond

In the following, you will find a list which assigns the scale for analysing the results from measurements in the hobby area and explains the symbols: The scales are described from the top to the bottom here.

NO3: salt water, fresh water, garden pond

pH 6.0 – 7.6: fresh water, garden ponds

pH 7.4 – 9.0: salt water, fresh water, garden pond

Fe: fresh water, garden pond

The following JBL tests have a uniform scale for all 2 or 3 hobby areas for analysis of the results from the measurements, as differentiation is no longer necessary:






pH 3-10