Testing of Aquaforest Calcium, Magnesium and KH Test Kits

Posté le 17 mars 2018 par

Knowing the parameters of your aquarium is a very important thing to master for the proper maintenance of a reef aquarium. If you make additions, it is imperative to do regular tests to monitor and ensure you get correct values.

Aquaforest offers a ‘TestPro’ family of Ca, Mg and KH colorimetric test kits to measure their respective concentrations in the water of seawater aquariums.

This type of test can be use on a weekly basis, for example to have quick results, unlike a Marinlabl ICP-OES test which is thinner and complete but more expensive and requires a delay to get the results. In fact, both are complementary.

Each of the three kit boxes contains all the equipment necessary for carrying out the concentration measurements.

Let’s go to the descriptions, generalities and specificities as well as the uses of the three different kits.

In addition to the necessary to carry out the tests, each of the boxes contains a reference solution of 15 ml which makes possible several tests if you wish to test the kit itself with a calibrated solution. It is a good idea to do tests to confirm, for example, that the kit is still valid in time. Of course do not to pollute this reference solution. It’s necessary to think about margins +/-, measures, possible for each kit. For this, refer to each quality certificate provided for each kit to give you a right idea.

For the handling of these kits, tests with marine aquarium water and tests with the reference solutions provided and more have been made.

Both types of reference solution

The Calcium kit

Box contents

Contents of the box for the Ca kit
This kit allows to do between 55 and 65 tests. This variability is related to the calcium concentration of your aquarium that will influence the consumption of reagent C-Ca.

  • 1 reagent A-Ca container
  • 3 reagent B-Ca – 10 ml bottle
  • 1 reagent C-Ca – 50 ml bottle
  • 1 test vial
  • 1 syringe – 3 ml
  • 1 syringe – 1 ml
  • 1 syringe tip for the 1 ml syringe
  • 1 measuring spoon
  • 1 multilingual instruction manual and 1 graphic instruction manual
  • 1 quality certificate referencing batch and date
  • 1 reference solution – 15 ml (Ca, Mg, Density)
  • 1 flyer about Aquaforest products (English)

Performing the Ca test

Performing the test is fairly standard for a colorimetric test using 3 reagents. The principle is the addition of the first two reagents, then the dosage with the third which allows deducing the Ca concentration in your water. I let you read the manual for more details.
Graphic instruction manual for the Ca kit

The determination of the concentration is based on the ‘moment’ of the color change. At the beginning of the test the color of the vial is pink, then goes through the violet to reach the blue which is the indicator that we added enough reagent and that we are at the end of the measurement.

The difference in color is clearly visible between pink and blue. At the appearance of violet, intermediate color, it is necessary to shake the vial for 10 s before adding the reagent. The transition from pink to blue can be done in 1 or 2 drops. At this stage, the reagent C consumption is read, which makes it possible to determine the concentration of Ca in mg / l using the scale provided on the manual and the graphic instruction manual.

As there are 3 bottles of reagent B-Ca, I recommend you to identify the bottle used to avoid having several bottles open, this for a better conservation of the kit.

Color evolution during the test

Test capacity and accuracy

The kit allows testing from 0 to 500 mg / l using the scale chart provided. The manual even specifies how to measure beyond when necessary.

The scale and dosage of the reagents make possible to obtain a reading with step of 5 mg / l in the range of 380 mg / l to 460 mg / l, and step of 10 mg / l outside.

Test with the calibration solution

The calibration solution is provided for a concentration of 425 mg / l ± 1%. The use of the test kit on the calibration solution (3 measurements) gave me a concentration of 425 mg / l. This measurement is not a reference but a simple use of the test that I have done with all the errors that this may entail. Here we have exactly the expected value, the certificate mentioning a value of 420 to 430 mg / l.

The use of a reference solution from another brand gave me an equivalent result.

The Magnesium kit

Box contents

This kit allows to do between 55 and 60 tests. This variability is related to the concentration of Mg in your aquarium that will influence the consumption of reagent D (the concentration of calcium also influences the consumption of reagent A).
  • 2 reagent A-Mg – 10 ml bottle
  • 1 reagent B-Mg – 10 ml bottle
  • 1 reagent C-Mg container
  • 1 reagent D-Mg – 50 ml bottle
  • 1 test vial
  • 1 syringe – 3 ml
  • 1 syringe – 1 ml
  • 1 syringe tip for the 1 ml syringe
  • 1 measuring spoon
  • 1 multilingual instruction manual and 1 graphic instruction manual
  • 1 quality certificate referencing batch and date
  • 1 reference solution – 15 ml (Ca, Mg, Density)
  • 1 flyer about Aquaforest products (English)

Performing the Mg test

As for the Ca test, performing the Mg test is fairly standard with a colorimetric test using 4 reagents. The principle is the addition of the first three reagents, then the dosage with the fourth which allows deducing the concentration of Mg of your water. Note that knowing its Ca concentration before making the Mg assay can refine the accuracy via the more or less important use of reagent A-Mg. I let you read the manual for more details.

 

Graphic instruction manual for the Mg kit

The determination of the concentration is based on the ‘moment’ of the color change. At the beginning of the test the color of the flask is pink, goes through the violet, then to arrive at the blue which is the indicator that we added enough reagent D-Mg and that we are at the end of the measured. At this stage, the M-Mg reagent consumption is read, which allows the concentration of Mg in mg / l to be determined using the scale provided in the manual and in the leaflet.

As there are 2 bottles of reagent A-Mg, I recommend you to identify the bottle used to avoid having several bottles open, this for a better conservation of the kit.

Color evolution during the test

Test capacity and accuracy

The kit allows testing from 0 to 1500 mg / l using the scale chart provided. The manual even specifies how to measure beyond when necessary.

The scale and dosage of the reagents make possible to obtain a reading with a step of 10 to 20 mg / l in the range of 1200 mg / l to 1410 mg / l, and a step of 30 mg / l outside.

Given the measurement table it is verry important to use the tip of the syringe to add the last reagent in small drops.

Test with the calibration solution

The calibration solution is provided for a concentration of 1310 mg / l ± 1%. Using the test on the calibration solution (3 measurements) gives a concentration in the expected range. The certificate mentioning a value between 1290 and 1320 mg / l. This measurement is not a reference but a simple use of the test that I have done with all the errors that this may entail.

The Alkalinity kit

Box contents

This kit allows to do between 78 to 100 tests. This variability is related to the concentration of Alkalinity (KH) in your aquarium that will influence the consumption of the B-KH reagent.

  • 1 reagent A-KH – 10 ml bottle
  • 1 reagent B-KH – 10 ml bottle
  • 1 syringe – 3 ml
  • 1 syringe – 1 ml
  • 1 syringe tip for the 1 ml syringe
  • 1 multilingual instruction manual and 1 graphic instruction manual
  • 1 quality certificate referencing bach and date
  • 1 reference solution – 15 ml (Ca, Mg, Density)
  • 1 flyer about Aquaforest products (English)

Performing the KH test

As for the Ca and Mg tests, the performance of the Alkalinity test is fairly standard with a colorimetric test using 2 reagents. The principle is the addition of the first reagent, then the dosage with the second which allows deducing the KH concentration of your water. I let you read the manual for more details.
Graphic instruction manual for the KH kit

The determination of the concentration is based on the ‘moment’ of the color change. At the beginning of the test the color of the vial is blue, and then goes through the violet to reach the rose which is the indicator that we added enough reagent. B-KH reagent consumption is used to determine Alkalinity in d° KH using the scale provided in the manual and the graphic instruction manual.

The difference in color is clearly visible between blue and pink.

Color evolution during the test

Test capacity and accuracy

The kit allows to test from 0 to 14 d° KH using the scale chart provided. The manual even specifies how to measure beyond when necessary.

The scale and the dosages make it possible to obtain a reading step of 0.3 d° KH over the range of use for our aquariums.

Test with the calibration solution

The calibration solution is provided for an Alkalinity of 7.3 d° KH ± 1%. Using the test on the calibration solution (3 measurements) gave me a measurement of 7.3 d° KH. This measurement is not a reference but a simple use of the test that I have done with all the errors that this may entail. Here we have exactly the expected value, the certificate mentioning a value of 7.0 to 7.6 d° KH.

The use of a test of another trade gave me an equivalent result.

Conclusion

Aquaforest Ca, Mg and Alkalinity Test Kits are colorimetric tests that can be easily used for regular measurements of these aquarium water concentrations.

The boxes include all the accessories to make the measurements. Multiple syringes are provided in kits to avoid mixing reagents and water samples from the aquarium. A tip for 1 ml syringes is provided. It allows dosing with smaller drops and therefore more accurately than without this tip. The instructions provided are clear and include a table to convert the value read concentration value without making a calculation. A mini ‘graphical’ instruction manual allows you to recall the test sequence when you have already read the more detailed instruction manual for the first time.

The color differences and their transitions are clearly visible, which allows easier use and contributes to a good repeatability of the tests.

The test kits are tested with identified batch and with a certificate provided. Between the date of the batch, on the certificate card, and the label under the boxes, we note that the kits are given as being valid for a duration of 2 years and 9 months.

The reference solution that is provided for each kit is significant. It can help to remove doubts of validity, especially in time. To keep carefully to do not contaminate it.


Price: 14.90 € for the Ca and Mg tests, 9.90 € for the KH test

Manufacturer information: Aquaforest test kits

 

French version / Version Française

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