For high precision determination of the concentration of nitrite and nitrate:
Nitrate ions (NO 3 – ) come from the nitrification of ammonium (NH 4 + ). The first partial steps of the bacterial process generate nitrite (NO 2 – ) which is extremely harmful to freshwater animals. When nitrification works well, the nitrite turns into a comparatively non-toxic nitrate in a second step. Nitrite values above 0.05 mg/l mainly concern pools in the running-in phase or equipped with nitrate filters.
Nitrate has an influence on the quality of aquarium water: In saltwater aquariums, too high concentrations of nitrate interfere with the growth of fragile corals. In all aquariums, a high nitrate content leads to the risk of strong algae growth. Some coral aquariums are subject to extremely low nutrient conditions which in some cases can lead to a lack of nitrate. The nitrate concentration of the aquarium water should therefore be checked regularly. For freshwater aquaria, nitrate levels of 50 mg/l are recommended, while for saltwater concentrations should not exceed 20 mg/l. For hard coral farming, nitrate levels below 10 mg/l should be targeted. Lower nitrate thresholds depend on general aquarium conditions.
Advantages :
| • | Measuring range: NO 2 0 – 1.0 mg/l |
| • | Measuring range: NO 3 0 – 20 mg/l |
| • | Accuracy: NO 2 0.002 mg/l |
| • | Accuracy: NO 3 0.05 mg/l |
| • | For determining the concentration of nitrite and nitrate |
| • | Incl. comparator |
| • | Includes phosphate standard to verify function and shelf life of test reagents |
| • | Sufficient for about 50 applications |
Manual :
Nitrite determination:
| 1. | Before use, shake the bottles well! |
| 2. | Rinse the glass bowl several times with tap water, then with aquarium water. |
| 3. | Using the dosing syringe, pour precisely 15 ml of aquarium water into the glass cuvette and into the comparator which serves as a support for the cuvette. |
| 4. | Place the tip on the 1 ml syringe, pour 1 ml of test reagent A, close the glass cuvette with the stopper, briefly shake the sample and put it back in the comparator. |
| 5. | Then add 4 drops of test reagent C, close the glass cuvette again, shake briefly and place back in the comparator. |
| 6. | After 3 minutes of development time, place the glass cuvette in the comparator on the white circles of the nitrite color chart so that the second free opening of the comparator (without cuvette) is inside the chart colorimetric (and not on the colored areas) and that the narrow front face of the comparators is oriented in the direction of the colored areas. The color of the water sample is then compared with the colored areas opposite to daylight. To do this, observe from above the inside of the open bowl. Move the sample on the color chart until the cuvette and the colored area show the same color. |
| 7. | Read the nitrite value under the corresponding colored area. If the colors do not match exactly, deduce an intermediate value. |
Nitrate determination:
| 1. | Before use, shake the bottles well! |
| 2. | Rinse the glass bowl several times with tap water, then with aquarium water. |
| 3. | Using the dosing syringe, pour precisely 15 ml of aquarium water into the glass cuvette and into the comparator which serves as a support for the cuvette. |
| 4. | Place the tip on the 1 ml dosing syringe, draw up 1 ml of test reagent A and pour it into the water sample. Close the glass cuvette with the stopper, briefly shake the sample and put it back in the comparator. |
| 5. | Shake the bottle of test reagent B very vigorously for approx. 30 seconds (reagent must be stirred). Then add 10 drops of test reagent B to the sample in the aquarium, close the cuvette, shake briefly and place back in the comparator. |
| 6. | After 3 minutes of development time, add 4 drops of test reagent C, close the glass cuvette again, swirl briefly and replace in the comparator. |
| 7. | After 3 minutes of additional development time, place the comparator on the white circles of the nitrate color card so that the second free opening of the comparator (without cuvette) is inside the color card (and not on the colored areas) and that the narrow front face of the comparators is oriented in the direction of the colored areas. Observe from above the interior of the open cuvette and compare with the colored areas opposite to the daylight. Move the sample on the color chart until the cuvette and the colored area show the same color. |
| 8. | Read the nitrate value under the corresponding colored area. If the colors do not match exactly, deduce an intermediate value. |
| 9. | After the measurement process is complete, rinse the glass cuvette, syringe and syringe tip thoroughly with tap water. |
Noticed
Nitrite concentrations affect the nitrate measurement. Therefore, before carrying out a nitrate measurement, the nitrite concentration should also be measured and the results should be corrected according to the table if necessary. High nitrite values primarily affect aquariums in the early stages or with nitrate filters.
Application of the “Standard” solution to control the test
As far as titration tests are concerned, the functionality is generally time-limited. For example, the durability of reagents depends among other things on the storage conditions. If they are no longer sufficiently functional, the test no longer results in staining even with high nitrate values. To check the reliability of the test in the case of a measurement result lower than 1 mg/l, add 5 drops of the Standard reference solution to a new sample. If during this new test a pink color appears (2 mg/l), the reliability of the reagents is guaranteed.
