Go back a few years & the internet abounds with nitrate shock, nitrate toxicity posts & articles
Somehow this has transformed into a seeming collective nitrate is benign regardless of concentrations or sudden elevations 😕
I'm sort of a Science person 😉
And therefore, the conclusion, evidently, is that a few years ago, the information on the internet, abounding with
nitrate shock,
nitrate toxicity posts & articles must have been true, while the latest information reporting benign nitrate must be false.
It seems odd that a Science persons, typically known for their attention to detail, would interpret the transformation as "...
nitrate is benign regardless of concentrations or sudden elevations..."
I don't recall our ever stating that or ever reading any articles to that effect. What we have stated and have seen clearly delineated in the articles is that the level of NO3 that we dose in our eutrophic dosing schemes doesn't come anywhere near the reported toxic levels reported in the articles. In fact the dosing schemes provide NO3 levels at several orders of magnitude below the toxic levels stated in the articles -even when added to the resident NO3 levels in tap, we are still far below any acutes or chronic toxic levels.
...while there are some species that appear resistant to even very high levels of nitrates ie no apparent effect observed on behaviour or growth, eg, channel catfish - I'm not much interested in keeping channel catfish in my aquaria so while I've read several articles I'm not inclined to dig out the links (that few seem interested in reading anyway
🙂 ) -
I suspect that the ornamental fish I do keep in my aquarium share more properties with zebrafish
Nitrate and nitrite exposure affect cognitive behavior and oxygen consumption during exercise in zebrafish
Zebrafish have been avid science contributors for decades
(I'd be surprised if the human nitrate guidelines didn't begin with zebrafish experiments)
Again, as mentioned by other posters, 607 ppm NaNO3 yields a nitrate concentration of over 440 ppm - that is 10X the highest level of NO3 in European tap and over 20X the EI dosing level.
.There are significant papers confirming biochemical effects of nitrate exposure to support your concern
Yes, I'm sure there are enough papers that if interpreted properly, will support whatever confirmation bias is necessary to support all kinds of fears.
Lets extract some data from this paper:
Meade and Watts (1995) examined the toxic effects of NaNO3 on the survival and metabolic rate (oxygen consumption) in juvenile individuals (9–13 mm total length) of the Australian freshwater crayfish
Cherax quadricarinatus. After 5 days, no mortality was observed in crayfish exposed to a nominal nitrate concentration of 1000 mg NO3-N/l. Furthermore, no significant difference was observed in oxygen consumption between control (0 mg NO3-N/l) and experimental (1000 mg NO3-N/l) individuals [this yields a Nitrate concentration of 4300 ppm].
Rubin and Elmaraghy (1977), after examining the acute toxicity of KNO3 to guppy (
Poecilia reticulatus) fry, calculated 24, 48, 72 and 96 h LC50 values of 267, 219, 199 and 191 mg NO3-N/l
This last example should be illustrative of what we have been stating repeatedly. In order to kill
50% of a sample of guppy
fry it required in this experiment: 1150 ppm NO3 (24 hours), 940 ppm (48 hours), 855 ppm (72 hours) and 821 ppm (96 hours).
Now, if Science persons are too lazy to look at these numbers and to compare them to the numbers in the dosing schemes then they will not be able to reconcile our statements regarding the benign nature of NO3 dosing.
If folks want to maintain their fear of NO3, which is actually natures way of detoxifying the environment against the highly toxic NH3 and NO2, then there is nothing that can be said to change their opinion. In fact, my contention is that the OP is not even asking the right question. What he should be asking is what plants are the most NH3/NH4 guzzling.
I reiterate that being paranoid about NO3 leads the hobbyist into making the wrong decisions and turning him/her away from potentially problem solving paths.
Cheers,