Water tests: here's how to test correctly

Water tests help you to „understand“ your aquarium, to pinpoint problems and give you the opportunity to correct the water parameters so that your fish, invertebrates and plants feel comfortable.

There are various kinds of tests

Depending on the procedure we distinguish between the following types of water tests:

Colour comparison tests

Fill two cuvettes with your aquarium water. Put one cuvette on a colour field of the colour chart to take any inherent water colouring during the reading of the colour into account (JBL comparator system). For better handling put the cuvettes into the plastic holder which you can move back and forth on the colour chart’s colour fields. Place the second cuvetter on a white field and add indicators which colour the water. Now compare the resulting colour with the colour on the colour chart and read the value.

Colour change tests

JBL KH Test , JBL GH Test , JBL CO₂ Direct Test Set , JBL K Potassium Test Set , JBL Mg Magnesium Test Set Freshwater

Add water from your aquarium into a cuvette. Add the indicator dropwise until the colour changes. Depending on the test the colour change is different, e.g. from blue to orange, using the carbonate hardness test. The number of the drops you need for the colour change to occur equates to the height of the measured value. If you, for example, use 5 drops until the colour blue changes into orange, the carbonate hardness would be 5 °dKH.

Turbidimetric test

This includes the JBL K Potassium Test Set . With the help of reagents and your aquarium water you produce a cloudy, whitish liquid which you add little by little into a test tube with a scale, until the cross below the test tube is no longer recognisable from above. The scale then tells you how much potassium is available in your water.

Permanent test

This includes the JBL CO2-pH Permanent Test . Add an indicator to a tranparent vessel, which is attached to the inside of your aquarium pane. The indicator reacts with the CO2 from your aquarium water and indicates, depending on the CO2 quantity, a specific colour which can be compared with an affixed scale. This way you can read the CO2 content on a 24-hour basis!

Test strips

These include the JBL EasyTest 6in1 and JBL ProScan . The strips test pH, GH, KH, NO2; NO3, chlorine and calculate the CO2 content (only JBL ProScan). JBL ProScan ).

Dip a test strip into your aquarium water for three seconds, dab it several times HORIZONTALLY that excessive water can drip off and compare it with a colour scale which shows you the resulting value. For JBL ProScan put the test strip onto a special colour chart from which you take a photo with your smartphone and a free ProScan app after a waiting time of 60 seconds. The app reads out the colours and gives you the resulting values extremely precisely, plus a recommendation how to improve your water parameters.

You can read what your results mean here:

As soon as you have carried out a test, you will receive a result (e.g. in milligrammes per litre (mg/l)). This will show you how to interpret the result and whether any further steps are required to optimise the water.

Water values

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

Tips for carrying out the water tests

Always hold the bottles with the indicator liquids vertically. Then the drop size is always the same.

Always discard the first drop since it is not always full sized. Keep a light pressure on the bottle after the first drop, so that no air is sucked in and all the following drops come out steadily.

Always position the cuvettes on a white background to better recognise the colours during the colour change tests.

Always thoroughly rinse the cuvettes with tap water after testing (better would be distilled water – JBL Dest ).

If your test has a comparator block, please use it!! A manual moving of the glass vials on the colour charts WITHOUT a comparator block leads to a different colour perception, because the plastic block throws a shadow onto the liquid part of the vials.

For JBL ProScan you need to know the following: don’t shake the water off after dipping the test strip as you would shake a fever thermometer. It’s better to tap it gently on a cloth or on absorbant paper. Make sure your mobile phone doesn’t cast a shadow when photographing the colour chart with the test strip.