Zero nitrates

[Country joe]

After cycling my aquarium test results are stable, but my nitrate tests have always been nil. I have quite a few plants, on the nil nitrate, I've been advised to use TNC complete plant food, as it contains nitrate, but it also has phosphate, but on their info it says, this product will not encourage algae, do you think this will be right, and is it good to up my nitrate level from nil.

 

[Essjay]

Unless you have a high tech tank with strong light, added CO2 and lots of fertiliser, you don't need to add nitrate.
Plants prefer ammonia. They only use nitrate if they run out of ammonia. Plants have to turn nitrate into ammonia to use it, and this takes energy. Why waste that energy if there's ammonia in the water ready to use?

In a non-high tech tank (which has easy plants which don't need added CO2 or masses of fertiliser) the fish provide enough ammonia for the plants.

 

[Essjay]

This is another debatable point, plants using or not using nitrate.

Most aquarium plants prefer ammonia/ammonium, and will ignore nitrate if the ammonia/ammonium is in balance with all other nutrients and the light. They will not switch to nitrate (or nitrite) under normal circumstances (low-tech, natural method planted tank) because chances are the light and other nutrients (esp carbon here) will not be sufficient. And it takes plants about 24 hours to change gears. And, when they do, they have to then spend considerable energy changing the nitrate back into ammonium so they can use it. So, it is not surprising that they tend to ignore nitrate. [In high-tech systems it is very different.]

Diana Walstad goes into all this is great detail in her book Ecology of the Planted Aquarium, citing numerous scientific studies.

Also, there is denitrification. Bacteria that use nitrate to create oxygen. And, there is the change from nitrate to nitrogen gas that then escapes back into the atmosphere at the surface.

 

[sharkweek178]

After cycling my aquarium test results are stable, but my nitrate tests have always been nil. I have quite a few plants, on the nil nitrate, I've been advised to use TNC complete plant food, as it contains nitrate, but it also has phosphate, but on their info it says, this product will not encourage algae, do you think this will be right, and is it good to up my nitrate level from nil.

Are you using the API Master Test Kit? If so, that nitrate test can be a little tricky to get an accurate reading. You have to shake bottle 2 good and hard for at least 2 minutes then when you add that to the test tube, give the test tube a good hard shake for 1 minute. Otherwise, you might not get accurate results.

 

[Country joe]

Are you using the API Master Test Kit? If so, that nitrate test can be a little tricky to get an accurate reading. You have to shake bottle 2 good and hard for at least 2 minutes then when you add that to the test tube, give the test tube a good hard shake for 1 minute. Otherwise, you might not get accurate results.

Thanks, I use NT labs.test kit, and yes I did all the proper shake,

 

[Uberhoust]

FYI a quick look at the color chart for the NT labs Nitrate appears to use the same type of reagents as the Fluval Nitrate test kit. If so, it is also very sensitive to the second regent not being agitated enough. With the Fluval version of the Nitrate test kit I was getting 0 nitrate readings with a known solution of 20 ppm or more nitrate. I could not get the Fluval kit to work correctly and fluval sent me a replacement which did work. Just saying I don't trust 0 nitrate readings from Fluval, or API, especially if common sense suggests that they should be none zero.

 

[10 Tanks]

Hello. The plant requires nitrogen, phosphate and potassium. It will grow if it has a steady supply of these nutrients. However, nitrogen in the form of ammonia and nitrite need to be removed from the water for the fish to live. Ideally, you want nitrate to be in the 20 to 30 parts per million range for the plants to grow.

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