Tropic Marin test Nitrite/Nitrate (NO2/NO3) – Review
For nitrates, Tropic Marin recommends a level up to 20 mg/l for freshwater aquariums, with 80 mg/l maximum and 100 mg/l considered dangerous. For marine tanks the level should never exceed the 20 mg/l if only fishes are kept, while for corals it should not go above 10 mg/l. We at DaniReef would like to add that for SPS coral colourations the level should be even lower.
The nitrate test would be spoiled by a nitrite concentration higher than 0.05 mg/l. It is good to have both tests, then, to make sure we are reading a reliable value.
To carry out the test we add 10 drops of reagent A to the 5 ml tank water in the cuvette, shake gently then add a spoonful of reagent B, shake gently again then add reagent C. Wait for 3 minutes before comparing the colour with the chromatic scale. The values range between <1, 2, 5, 10, 15, 30, 50, 100, a wide scale which allows us to measure values for freshwater tanks or ponds, but also detailed enough on the lower end for the marine tanks (up to 10 mg/l).
The test was repeated and interpreted by two different individuals, just like for nitrites. At the first trial we read a 2 mg/l value, at the second one of us read a 5 mg/l while the other remained on the 2 mg/l. This test, though, seemed a bit easier to read even if the colours are the same, maybe because being further from the 0 the colours are more vivid and easier to interpret.
This time we compared the result with another test brand, Salifert, which uses a high sensitivity scale and gave us a result of 5 mg/l. This value is a bit higher than what we found, but not much. We are still sorry for the reference test nature.
Test Kit Duration
There are a few doubts regarding the Tropic Marin Nitrite Nitrate test that we’d like to clarify. Firstly, in the Expert Testset we read a maximum duration of 6 months from the opening, while in the single test it says 12 months. We asked Tropic Marin directly, and they informed us that this test does have a limited duration and it is guaranteed to work for 6 months only. We can still verify the reliability of the test and use it for longer.
Moreover, a specific passage on the Italian instruction booklet is not very comprehensible. As we said, we can verify the test integrity by doing a small test using the reagent D. In this case, by reading the instruction it might sound like we have to use the reagent D in the same cuvette in which we read a result lower than 5 mg/l. But it really means that only after a result lower than 5 mg/l we might want to test the quality of our reagents, and to do so we have to repeat the test with new water and adding 5 drops of reagent D, then the reagents for a normal test. If the value read is equal or more than 30 mg/l, we can consider the previous result as reliable.
The only issue with the Tropic Marin Nitrite Nitrate test is the chromatic scale interpretation. With a good light and exercise (also by placing the cuvette near the colour sheet) the test results should become unambiguous. The test repeatability was optimal. It was a shame not having the possibility to do a lab test to compare results.
The test is easy to carry out and during the 3 minutes wait for one we can start the other (and reading the scale of the first during the second 3 minutes wait), this allows us to optimize our time.
In case you need it here is the multilingual instruction leaflet.
Easy to carry out
Possibility to verify test reagent state
Difficult to read chromatic scale
The only issue with the Tropic Marin Nitrite Nitrate test is the chromatic scale interpretation. With a good light and exercise (also by placing the cuvette near the colour sheet) the test results should become unambiguous. The test repeatability was optimal.