# Nitrate tests?



## Muso1981 (29 Aug 2020)

Hi all,

I'm new to the forum but have basically had a tropical planted tank for about two years. I'm trying to get my tank into a situation whereby the plants manage the nitrates and was wondering if anyone's had success with that? In addition to the plants in my tank I've also got a pothos growing out the top.

All the water readings in my tank are good except for Nitrates, but my issue is with the tests. I've currently got two tests and they both give very different readings. The NT labs test data my nitrate levels are low whereas the Tetra says they are high. 

I'd really like to know of an accurate test or at least something half decent and if anyone has any tips for me.

Cheers!


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## ian_m (29 Aug 2020)

https://www.ukaps.org/forum/threads/what-about-test-kits.52487/


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## Muso1981 (29 Aug 2020)

Thanks but I couldn't see any solution for my particular situation.

I did a forum search before posting this but not much came up.

What Nitrate test do you use Ian?


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## hypnogogia (29 Aug 2020)

I think a few people on here (Including myself) use the JBL Nitrate Test.


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## dw1305 (29 Aug 2020)

Hi all, 





Muso1981 said:


> All the water readings in my tank are good except for Nitrates, but my issue is with the tests.





Muso1981 said:


> The NT labs test data my nitrate levels are low whereas the Tetra says they are high.


There are some possible issues <"with nitrate testing">. 

What does the <"plant growth"> look like?

cheers Darrel


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## Muso1981 (30 Aug 2020)

Hi plant growth is absolutely fine, everything seems ok but I'm just concerned about nitrate levels and the effects that might have on fish health.

Thanks for the recommendation I've bought the JBL test kit.


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## alto (30 Aug 2020)

Muso1981 said:


> I'd really like to know of an accurate test or at least something half decent and if anyone has any tips for me.


Look for test kits that include reference standards as then one can rule out various complications 

eg, Seachem 
https://www.seachem.com/multitest-nitrite.php

Includes reference for test validation
It’s worth checking with your water supplier for a comprehensive analysis (often available  online)
If your tap water contains 30ppm nitrates, then expect your tank to run 10-20ppm above this depending upon your maintenance and feeding, bioload, plant growth and fertilizers etc


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## alto (30 Aug 2020)

Muso1981 said:


> In addition to the plants in my tank I've also got a pothos growing out the top.


If the pothos plant is thriving, it may remove nutrients that your aquarium plants need (also block light depending) so monitor aquarium plant growth/health


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## dw1305 (31 Aug 2020)

Hi all,





Muso1981 said:


> Hi plant growth is absolutely fine, everything seems ok but I'm just concerned about nitrate levels and the effects that might have on fish health.


I'd probably look on the <"healthy growing plants as the important bit">.

cheers Darrel


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## ian_m (1 Sep 2020)

Muso1981 said:


> What Nitrate test do you use Ian?


I don't use any test at all, read the link I sent as to why you are wasting money using hobby grade test kits. Never tested my water or tank, absolutely no point. Plants grow like mad, fish thrive & breed like mad, so nitrate levels must be  OK, what ever level that is.

Hobby grade nitrate test are notoriously fickle and results, as you have found, can be very variable as the results are greatly influenced by other salts/ions present in tank water.

Why do you require a nitrate value ? What can you do if you get 50ppm, 150ppm ? Ok you read 50ppm, with a hobby grade test kit, can you trust the result ? What you you going to do about it ? 50ppm is brilliant for plants, they will soon mop it up. Fish can tolerate quite high ppm, possibly in order of 1000ppm, though not recommended.

A lot of research on high nitrates and fish is based upon organic sourced nitrates, ie rotting plants/fish as nitrite source,along with many other organic, possibly toxic compounds, as opposed to inorganic sourced nitrates being dosed as plant food. So difficult to draw conclusions about fish and nitrate levels. After a pump failure I accidentally dose massive dose of nitrates, about 350ppm for over a week, and saw no fish issues, or more sadly no change in plant growth.

So don't test, one less worry and just work what water and tank you have.

If you really insist on testing, a lab grade nitrate test kit can be more reliable. Something like this may give more reliable results.
https://www.camlab.co.uk/nitrate-nitrite-test-kit-ni-12


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## alto (2 Sep 2020)

ian_m said:


> A lot of research on high nitrates and fish is based upon organic sourced nitrates, ie rotting plants/fish as nitrite source,along with many other organic, possibly toxic compounds, as opposed to inorganic sourced nitrates


Can you provide links?



I find this methodology to be more typical of journal published studies
*Comparing the effects of high vs. low nitrate on the health, performance, and welfare of juvenile rainbow trout Oncorhynchus mykiss within water recirculating aquaculture systems*

John Davidson, Christopher Good, Carla Welsh, Steven T. Summerfelt
https://www.sciencedirect.com/science/article/pii/S0144860914000041



> Nitrate nitrogen concentrations for the high treatment were controlled by continuously dosing a sodium nitrate stock solution into the LHO sump using a peristaltic pump, in addition to the natural accumulation resulting as an end product of nitrification. Nitrate nitrogen concentrations within the control systems were created only as an end product of the nitrification process and controlled by water exchange. All fluidized sand biofilters were fully acclimated and capable of complete nitrification when the study began. In addition, a sodium sulfate solution was continuously dosed to the low NO3-N systems using a peristaltic pump in order to balance the sodium concentration and conductivity between treatments.





I don’t recall any (recent) study where


ian_m said:


> organic sourced nitrates, ie rotting plants/fish


was employed as the nitrogen source



This literature review published in 2005 rather disagrees with your determination that nitrates are innocuous to fish even at much lower levels (than you’re advocating)

*Nitrate toxicity to aquatic animals: a review with new data for freshwater invertebrates.*

J. Camargo, Á. Alonso, Annabella Salamanca



> Published data on nitrate (NO3-) toxicity to freshwater and marine animals are reviewed. New data on nitrate toxicity to the freshwater invertebrates Eulimnogammarus toletanus, Echinogammarus echinosetosus and Hydropsyche exocellata are also presented. The main toxic action of nitrate is due to the conversion of oxygen-carrying pigments to forms that are incapable of carrying oxygen. Nitrate toxicity to aquatic animals increases with increasing nitrate concentrations and exposure times. In contrast, nitrate toxicity may decrease with increasing body size, water salinity, and environmental adaptation. Freshwater animals appear to be more sensitive to nitrate than marine animals. A nitrate concentration of 10 mg NO3-N/l (USA federal maximum level for drinking water) can adversely affect, at least during long-term exposures, freshwater invertebrates (E. toletanus, E. echinosetosus, Cheumatopsyche pettiti, Hydropsyche occidentalis), fishes (Oncorhynchus mykiss, Oncorhynchus tshawytscha, Salmo clarki), and amphibians (Pseudacris triseriata, Rana pipiens, Rana temporaria, Bufo bufo). Safe levels below this nitrate concentration are recommended to protect sensitive freshwater animals from nitrate pollution. Furthermore, a maximum level of 2 mg NO3-N/l would be appropriate for protecting the most sensitive freshwater species. In the case of marine animals, a maximum level of 20 mg NO3-N/l may in general be acceptable. However, early developmental stages of some marine invertebrates, that are well adapted to low nitrate concentrations, may be so susceptible to nitrate as sensitive freshwater invertebrates.





Nitrate Toxicity on Visceral Organs of Medaka Fish, Oryzias latipes : Aiming to Raise Fish from Egg to Egg in Space

Ryuji Shimura, Ying X. Ma, Kenichi Ijiri, Shunji Nagaoka, Minoru Uchiyama



> Histological survey was made to determine nitrate toxicity on the Medaka fish, Oryzias latipes. In order to investigate the effects of short-term exposure to nitrate, one-month-old Medaka fish was exposed to NaNO3 at concentrations of 100 and 125 mg NO3-N l-1 for 96 hours. At the end of the exposure period, survival rate was found to be 30% and 10%, for the 100 and 125 mg NO3-N l-1 exposure concentrations, respectively. Histological examination of the organs showed that disruption of cell alignment was a common feature in the gills, intestinal ampulla, liver and kidney. A long-term exposure experiment was also carried out, whereby Medaka fish was exposed to NaNO3 (100 and 125 mg NO3-N l-1) for three months from its egg stage. Eggs treated with NaNO3 hatched within 10 days after fertilization. At the end of the exposure period, survival rate in the 100 and 125 mg NO3-N l-1treatments were 40% and 30%, respectively. Fibrosis of the hepatic cells and curved spinal column were observed in the juveniles subjected to long-term nitrate exposure. The results of our experiments suggest that the high mortality resulting from short-term acute exposure to nitrate is caused by general dysfunction throughout the whole body. The chronic toxic effects attributed to nitrate, following long-term exposure, were likely to have resulted from nutrient deficiency caused by hepatic dysfunction.



A previous article (by same authors)

Aquatic animal research in space station and its issues — focus on support technology on nitrate toxicity



> We studied the effects of accumulated nitrate in water on the spawning, hatching and development of medaka using a simple nitrifying filter and a combined filter having both nitrifying and denitrifying capabilities. A nitrate concentration of 100mgNO3−-N/L was clearly of lethal toxicity to fish when they were exposed to nitrate in both adult and the growing phases. A nitrate concentration of 75mgNO3−-N/L reduced the fertilization rate, delayed the hatching time and reduced the hatching rate of the eggs laid by adults and decreased the growth rate of juveniles. In addition, nitrate accumulations as low as 50mgNO3−-N/L remarkably retarded spawning and lowered the number of eggs laid by fish exposed in the juvenile phase. The effects on the reproduction system may be initiated by a low concentration, approximately 30mgNO3−-N/L.


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## alto (2 Sep 2020)

Some fish species including zebrafish (danio rerio) are tolerant of much higher nitrate levels than those reported in the above quoted studies 
(recommendation for zebrafish in laboratories is 200mg/l ... depending)


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## dw1305 (2 Sep 2020)

Hi all, 





alto said:


> Comparing the effects of high vs. low nitrate on the health, performance, and welfare of juvenile rainbow trout _Oncorhynchus mykiss_ within water recirculating aquaculture systems.


Those are useful references, data from properly controlled experiments. 





> ..... Nitrate nitrogen concentrations for the high treatment were controlled by continuously dosing a sodium nitrate stock solution ....... in addition to the natural accumulation resulting as an end product of nitrification. Nitrate nitrogen concentrations within the control systems were created only as an end product of the nitrification process and controlled by water exchange. ...... In addition, a sodium sulfate solution.....


We have a few of these <"Salmonid Aquaculture papers">, that give similar figures.

Personally I wouldn't be happy with long term exposure of the fish to elevated NO3 levels, and even though I don't measure NO3 levels I'm confident that my tanks have low nitrate levels, because I have low conductivity (about 120 microS & NO3- is an ion) water and a <"lot of plant growth">.

Short term exposure would be slightly different, and I would definitely <"trade elevated levels of NO3-"> for elevated levels of NH3 or NO2-, as the latter two forms of fixed nitrogen will definitely kill your livestock. 

cheers Darrel


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## sparkyweasel (2 Sep 2020)

It's worth noting that  100 mg NO3-N l-1 (nitrate as nitrogen) is 442ppm NO3, - nitrate as measured by most hobby test kits. That's far above what we often think of as 'high nitrate'.


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## alto (3 Sep 2020)

ian_m said:


> If you really insist on testing, a lab grade nitrate test kit can be more reliable. Something like this may give more reliable results.
> https://www.camlab.co.uk/nitrate-nitrite-test-kit-ni-12



Hmmm I think I’ll spend that almost £300 (test kit and reference standard)on plants and hardscape instead 


If you insist on Hach, then this product would serve well enough for aquarium demands

Hach Nitrate and Nitrite Test Strips‚ 0 to 50 mg/L NO3--N; 0 to 3 mg/L NO2--N‚ 25 Strips/Bottle‚ 2745425

and even has an aquarium magazine write up at Reefs.com 
https://reefs.com/magazine/product-...e-ph-total-hardness-and-the-digital-titrator/




> *Test Strips – Nitrite and Nitrate*
> 
> Nitrite Range (as NO2-N): 0 – 3.0 milligrams per liter
> Nitrate Range (as NO3-N): 0 – 50 milligrams per liter
> ...





> *Test Strips – Nitrates (Low Range)*
> Value Estimated by Two Observers of the Test Strips: ‘Between 1 and 2 mg/l’ and ‘Between 2 and 5 mg/l.’
> 
> Actual Nitrate Measurement (as NO3-N): 3.6 mg/l





> *Test Strips – Nitrates (High Range)*
> Value Estimated by Two Observers of the Test Strips: ‘Between 1 and 2 mg/l’ and ‘Between 2 and 5 mg/l.’
> 
> Actual Nitrate Measurement (as NO3-N): 3.6 mg/l.



(note that the observers are consistent in their observations  )



> *Comments on Nitrite/Nitrate Test Strips*
> Generally, these strips reported values lower than those obtained with the laboratory instruments. This could be due to the presence of chlorides in the saltwater (chlorides exceeding 100 mg/l cause low results).


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## dw1305 (3 Sep 2020)

Hi all, 





alto said:


> .......Hmmm I think I’ll spend that almost £300 (test kit and reference standard)........


I'm not personally <"ever going back"> to regularly testing the tank water, but if I was in possession of the desire, a large amount of money and a surfeit of time, I would go down the <"Ion Selective Electrode"> route.  

If I was obliged to use wet chemistry,  I like the <"cadmium reduction,  diazo dye"> method in the <"Camlab kit">.  





alto said:


> This could be due to the presence of chlorides in the saltwater (chlorides exceeding 100 mg/l cause low results).


That is strange, because sea water has a <"known amount of chloride ions (Cl-)"> (about 19,400 mg/L) I would have expected that there would be a built in constant to take account of this?

cheers Darrel


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## alto (4 Sep 2020)

dw1305 said:


> That is strange, because sea water has a <"known amount of chloride ions (Cl-)"> (about 19,400 mg/L) I would have expected that there would be a built in constant to take account of this?


I was surprised that the article author wasn’t using a specific Salt Water Nitrate test kit but then I guess the objective was reviewing available strip tests (no idea when the article was written/published)


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## alto (4 Sep 2020)

dw1305 said:


> I would go down the <"Ion Selective Electrode"> route.


I breezed through a UK thesis project where the author reviewed all current portable water testing  tech for nitrates (and developed/tested a new methodology as his thesis work) ... seems the ion selective has some deficiencies in the field

Pretty much every nitrate method had various complications that made them rather less than ideal, hence the drive for a new kit


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## dw1305 (4 Sep 2020)

Hi all, 





alto said:


> Pretty much every nitrate method had various complications that made them rather less than ideal, hence the drive for a new kit


That is it. It has been slightly less problematic, in the student lab, <"using a NO3- ISE">.

I've been trying to buy a <"tryptophan fluorescence sensing sonde"> data logger for the small water course on campus, but we have a lot of "wants", and not a lot of money.

cheers Darrel


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