Nitrate And 40Ppm Question...

[eaglesaquarium]

Well, I lost a panda cory today, and my nitrate levels may have pushed up a bit higher than normal, because of my stupidity - increasing bioload due to spawning cories, mixed with a decrease in plants in the tank buffering against the nitrate...
 
Anyway, my nitrate pushed to 40ppm (maybe beyond!) between water changes and I lost a panda cory.  The rest of the fish look great, and I've performed a 50% water change (tap water nitrates run around 10-20 ppm).
 
 
 
The question is this:  is the 40ppm related to the ION nitrate, or the nitrogen atom.  I know the API test kit values are based on the ION, which means that 1ppm ammonia (NH3) becomes 2.7ppm nitrite (NO2) because its a heavier ion, and the nitrate 3.6ppm (NO3).  The key question is are we aiming for 40ppm nitrate by ION or by nitrogen atom?
 
 
If its the nitrogen atom, then 1ppm ammonia converts to 1ppm nitrite-nitrogen, and 1ppm nitrate-nitrogen. And according to the API test kit, the danger zone for the nitrate is actually higher on the scale than it appears.

 

[eaglesaquarium]

So... here's where I am getting confused:
 
 
1ppm ammonia would produce 2.7ppm nitrite (on the API test) and then 3.6ppm nitrate (again, on the API test).  So, when we cycle a tank with 4-5ppm (which is supposed to be how much ammonia is produced in a fully stocked tank), in a week's time, the amount of nitrate that should be produced as measured by the API test kit would be: 5ppm ammonia * 7 days = 35ppm ammonia. That would process into ~126ppm nitrate as measured by the API test kit, which would make sense for the kit to read as high as 160ppm.  (Afterall if 40 is the goal, then having a test kit that reads 4 times the acceptable limit makes no sense!)
 
 
And if we are counting the 40ppm rule as the goal for our tanks to not exceed, 35ppm ammonia (would actually be closer to 29ppm ammonia-nitrogen) and this would indicate that keeping our tanks under 40ppm would be fairly easy given regular maintenance and proper water changes, as this 29ppm ammonia-nitrogen would process into 29ppm nitrate-nitrogen.  
 
 
Conversely, if the 40ppm rule as the goal is talking about the ION, then 35ppm ammonia would process into 126ppm nitrate by the end of the week, and would require water changes on a nearly daily (or every other day) to keep the nitrate from rising too fast... (This is of course, assuming no live plants to take up any part of the nitrogen!)
 
 
So, am I correct in assuming that the 40ppm nitrate rule, is referring to 40ppm nitrate-nitrogen, and not the ion itself?

 

[daizeUK]

No, I'm pretty sure it's ion. 
 

Most aquarium authors give recommendations for acceptable nitrate levels in
terms of nitrate ion concentrations.  Recommendations for marine tanks range
from 10 to 40ppm nitrate ion for fish-only tanks [...] On the other hand, many
tests read in terms of nitrogen-ion concentrations, since this measure is
more commonly used by professionals.  Trouble often occurs when the hobbyist
measures her nitrate levels in nitrogen-ion concentrations and unwarily
compares the resulting number with a recommendation in ion concentrations,
possibly resulting in nitrate concentrations up to four times that intended.  Ref

 
I would guess either your tank is not producing 5ppm of ammonia a day or you have sufficient plants to remove most of the nitrates. 

 

[eaglesaquarium]

That makes sense, but then what does that mean about the 5ppm ammonia dose for a fishless cycle... seems rather superfluous.  I have a rather full tank (probably a bit OVER filled thanks to the breeding cories) and a fair amount of plants.  But, what about the person WITHOUT the live plants?  Many in the hobby keep no live plants to keep the nitrate levels down...  I wonder if that person can ever really maintain nitrates under 40ppm (ion scale).
 
 
 
So, the way I see it, either the 5ppm dose for a fishless cycle is FAR above what is necessary, or the nitrate battle for someone with no live plants is nearly impossible.
 
 
The good news is that I recently read some literature which states that aquatic plants PREFER to take nitrogen from the ammonia in the water, rather than nitrate, and that they PREFER to take ammonia through their leaves that any nitrogen source in the substrate.  I'll see if I can find the link again...  Which means that if the plants prefer to use the ammonia directly, the amount of ammonia that would actually be processed into nitrate would be FAR less than the 5ppm, because 1ppm ammonia converts to 3.6ppm nitrate, BUT its still only ONE nitrogen atom!  Which means if my plants are using the ammonia AS SOON AS produced by the fish, rather than the biofilter doing it, that would explain why my nitrates have been so low for so long...  I do need to boost my plant supply though, and probably change the lightbulb...

 

[daizeUK]

So, the way I see it, either the 5ppm dose for a fishless cycle is FAR above what is necessary, or the nitrate battle for someone with no live plants is nearly impossible.
 
Wish I could tell you my nitrates for comparison, but I'm not really in a position for that

  But I do know that my tap water contains about 40-50ppm nitrates off the bat, so without plants I've got no chance at all.  Another more realistic target I've heard is to aim for your tap nitrates plus 20ppm.   So assuming we're aiming for net production of 20ppm nitrates per week, that's about 0.8ppm ammonia per day after plant intervention.

 

[TwoTankAmin]

Basically you need to make sure what scale is being used when an author writes that X level of ammonia, nitrite or nitrate is given.
 
For a fishless cycle the researcher will almost always use two measure TAN (total ammonia nitrogen) expressed as ammonia-n. This may also be given as NH3-N. It is up to us as readers to pay attention and know which.
 
For example, Dr, Hovanec always states the the number as -n. So when he states one should never allow ammonia or nitrite to exceed 5 ppm, he makes it clear this is ammonia-n and nitrite-n. But most members here tend to use the API kit which does not measure on that scale. So if you want to follow Dr. ovanec's advice, you need to adjust either his numbers to be equivalent to those on the API kit or else adjust your test results to be equivalent to the scale he is using.
 
Now this is fine when it comes to ammonia. His 5ppm is about 6.5 ppm on the API kit and that kit will measure up to 8 ppm total ammonia ions. We run into problems with the nitrite kit. 5 ppm of nitrite-n translates into roughly 16.5 ppm on the total ion scale. And the API kit stops a 5 ppm.
 
Nitrate is a less clear situation as the research is more concentrated on ammonia and nitrite than on nitrate. But this may give you a bit of an idea:
 
 

The acute toxicity of unionized ammonia; nitrite and nitrate to the Indian major carp Catla catla (Hamilton) was determined using static and continuous flow through systems for 24 hours. The median lethal concentration (LC50) values for 24 h of ammonia (NH3-N), nitrite (NO2-N) and nitrate (NO3-N) were 0.045 mg/l, 120.84 mg/l and 1565.43 mg/l in static test respectively and were 0.036 mg/l, 117.43 mg/l and 1484.08 mg/l in continuous flow through test respectively.

from http/www.ncbi.nlm.nih.gov/pubmed/12602850
 
Now I realize this is a study of mortality, but it does give a good idea of how different the levels are are for each of the 3 nitrogen compounds. Not all the levels are given in -n scale. What one can take away from the study isn't any absolute rule for all fish but rather an understanding of the differences:
 
Ammonia-n at .045 ppm of NH3 killed 1/2 the fish in 24 hours.
Nitrite-n had to be at 120.84 ppm to do the same damage. That is 463 times the NH3 level..
Nitrate-n had to be at 1,565 ppm to do the same thing. That is almost 35,000 tines the ammonia concentration and 13 times the nitrite level.
 
If you are really curious, do a Google Scholar search for "toxicity of nitrate to fish"
 
Incidentally, your comments support the idea that one should always plant when cycling a tank at the outset. Because plants eat ammonia they will handle a certain portion of the normal cycling chores. This means one needs a smaller amount of bacteria to deal with ammonia etc. If one cycles a planted tank before the planting one is creating more bacteria than needed long term and thus also taking way more time to cycle than is needed as well. Read on Tom Barr's site and the folks there laugh at people who fishlessly cycle well planted tanks.
 
One last comment. In the states drinking water is required to contain not more than 10 ppm of Nitrate ( I do not know on which scale). However, this doesn't mean that will be what comes out of one's tap. Private pipes are not regulated- i.e. once the public water supply is connected to the homeowners pipes, the rules do not apply. In those private pipes it is very likely there are nirtifying bacterial colonies. These thrive on the ammonia caused by the breakdown of chloramines used in the treatment plant. Abd as we all know the end of nitrification in the absence of the final stage is nitrate.And this is the biggest cause of nitrate in our tap water.

 

[eaglesaquarium]

Not a scientific journal, but it does reference an article in one, written by the author of the wiki...
 
http/www.theaquariumwiki.com/Plants_and_Biological_Filtration#cite_note-ten-1
 
 
 
My current "cycling" tank is not what I would call "heavily planted".   The ratio there I believe for a true silent cycle is to plant nearly 75% of the substrate with stem plants.  I have maybe 5% planted with stem plants.  And my initial bioload of fish would be far more than are suggested in a silent cycle.  So, I took mature media from my home tank and seeded it into the new one and have been building it up in the meantime...  
 
 
 
I suppose I'm less concerned with the overall toxicity issue in the short-term than I am in the long-term husbandry "rule of thumb" which is usually discussed as 40ppm or elsewhere I've seen <50ppm nitrate.  But, generally, they don't discuss whether its NO3-N or just NO3.  I guess to play it safe its always best to err on the side of caution...

 

[TwoTankAmin]

The average person posting about 40 ppm or 80 ppm of nitrate being safe or harmful has no idea there are different scales nor what level of nitrate may or may not be harmful.
 
If one does weekly 35 - 50% waterchanges there should be no need to check nitrate concentrations. All the research literature uses ther NO3-N scale. For the most part it is only fry which might be really sensative to lower nitrate levels.
 
Most nitrate kits are not reliable anyhow.

 

[snazy]

Nearly all articles I've read about plants says they prefer ammonia rather than nitrAte so probably with plants in the tank the nitrAte levels can't rise so high.
Also, I remember there was a discussion a long time ago around here about how much ammonia the fish produce and that 5ppm ammonia daily in a fishless cycle is ridiculously high, totally unnecessary and slowing the cycle signifficantly because in a normally stocked tank fish won't go anywhere near that ammonia figure per day. I've never dosed so high myself.
And referring to tap water as far as I know the legal limit in US is 10mg NO3-N/L, UK is 11.3 NO3-N/L(50ppm NO3) 
Anyway, I found I found this table below.  Basically what I understand is that 1mg NO3-N/L(4.43ppm NO3) is very safe, and 2mg NO3-N/L(8.86ppm nitrate) is considered "appropriate for protection of the most sensitive freshwater species". And the difference of sensitivity from species to species vary and can be quite different, sometimes 10 or more times.
 
 
 
Camargo
 
et al. (2005) recommend (p1264) “… a maximum level of 2.0 mg NO3-N/L would be
appropriate for protection the most sensitive freshwater species”. This value is similar to that which we
have derived using the ANZECC (2000) and the Environment Canada (CCME 2007) methodology
with the updated chronic dataset. Notably, the Environment Canada (2003) derives a “interim” water
quality guideline of 2.9 mg NO3-N/L
 
Multiply by 4.43 to convert NO3-N(nitrate-nitrogen) to NO3(nitrate)
 
 

 

[eaglesaquarium]

The average person posting about 40 ppm or 80 ppm of nitrate being safe or harmful has no idea there are different scales nor what level of nitrate may or may not be harmful.
 
If one does weekly 35 - 50% waterchanges there should be no need to check nitrate concentrations. All the research literature uses ther NO3-N scale. For the most part it is only fry which might be really sensative to lower nitrate levels.
 
Most nitrate kits are not reliable anyhow.

 
No doubt about that...  I can get very different results just based on how much time lapses between my shaking of APIs bottle 2 and dispensing it.

 

[snazy]

The average person posting about 40 ppm or 80 ppm of nitrate being safe or harmful has no idea there are different scales nor what level of nitrate may or may not be harmful.

 
Well NO3-N levels at 40-80ppm will be in the hamful zone for quite a few, so logically the average person is right regardless, because these levels converted to NO3 are 177.2ppm and 354.4ppm, and in this case both can be harmful to some although not lethal for most.
As most info say, 5-10ppm max is recommended for very sensitive fish and invertebrates like shrimp, and it seems based on the above, it's about right, because this converted to NO3-N is about 1.13ppm and 2.25ppm respectively.
 
I don't bother taking too much into account my nitrAte either because the tests are ridiculous, but I've noticed that 50% water changes weekly keeps that under control in my tanks and it doesn't go beyond 10ppm for the most part although non-planted tanks are more of a trouble.  I measure the TDS instead compared to my tap water but then again my tap water barely has any nitrAtes.

 

[eaglesaquarium]

Nearly all articles I've read about plants says they prefer ammonia rather than nitrAte so probably with plants in the tank the nitrAte levels can't rise so high.
Also, I remember there was a discussion a long time ago around here about how much ammonia the fish produce and that 5ppm ammonia daily in a fishless cycle is ridiculously high, totally unnecessary and slowing the cycle signifficantly because in a normally stocked tank fish won't go anywhere near that ammonia figure per day. I've never dosed so high myself.
 

 
 
I wonder what a fully stocked tank of small shoaling variety of fish would produce daily as ammonia, assuming "normal" feeding.

 

[snazy]

Nearly all articles I've read about plants says they prefer ammonia rather than nitrAte so probably with plants in the tank the nitrAte levels can't rise so high.
Also, I remember there was a discussion a long time ago around here about how much ammonia the fish produce and that 5ppm ammonia daily in a fishless cycle is ridiculously high, totally unnecessary and slowing the cycle signifficantly because in a normally stocked tank fish won't go anywhere near that ammonia figure per day. I've never dosed so high myself.
 

 
 
I wonder what a fully stocked tank of small shoaling variety of fish would produce daily as ammonia, assuming "normal" feeding.

 
It would be interesting, but some fish need to be sacrificed in order to find out for sure. It also needs to be measured in how many mg, not mg/L(ppm) because the second would depend on the size of the tank. For example a group of fish that would produce 1mg/L(1ppm ammonia) in a 10 litre tank, would actually produce 0.1mg/L(0.1ppm) ammonia in a 100 litre tank.
 
The other option is a bare control tank, fully cycled filter, no plants, no nitrAte sponges, or something of the sort,  and using a digital nitrAte test measure the increase per week for the period of several weeks to be sure it's consistent, then convert that back to ammonia

 Then convert it from Mg/L to total Mg depending on the size of the tank used and you have a value of how much ammonia this particular group of fish would produce weekly/daily average. Not perfect but it will give a fairly good idea.

 

[TwoTankAmin]

Just like for ammonia and nitrite, nitrate toxicity is not a fixed number. What level may be safe, toxic or fatal is first species dependent and second usually life stage dependent. Normally, fry are more sensitive than older fish. Also, I would bet dollars to donuts most posters stating a given level of nitrates are harmful are using the ion scale.
 
When we read the test kits we are reading concentrations, so you can convert the numbers. If you know that X number of fish in a 10 L tank produced 1 ppm one can calculate that the same ammonia production in a 20 L tank would be .50 ppm and in a 100 L tank it would be .10 ppm. The more water, the more diluted the ammonia is and vice versa. Besides, we do not care about the amount of ammonia the fish produce per se, we care about the concentration of ammonia in the water.
 
Also, there is a correlation between fish ammonia output and the protein content of their diet, up to a certain point beyond which it makes no difference.
See figure 2:
Effects of dietary protein level on growth performance, carcass composition and ammonia excretion in juvenile silver perch
http/www.sciencedirect.com/science/article/pii/S0044848602001205

 

[eaglesaquarium]

Just like for ammonia and nitrite, nitrate toxicity is not a fixed number. What level may be safe, toxic or fatal is first species dependent and second usually life stage dependent. Normally, fry are more sensitive than older fish. Also, I would bet dollars to donuts most posters stating a given level of nitrates are harmful are using the ion scale.
 
When we read the test kits we are reading concentrations, so you can convert the numbers. If you know that X number of fish in a 10 L tank produced 1 ppm one can calculate that the same ammonia production in a 20 L tank would be .50 ppm and in a 100 L tank it would be .10 ppm. The more water, the more diluted the ammonia is and vice versa. Besides, we do not care about the amount of ammonia the fish produce per se, we care about the concentration of ammonia in the water.
 
Also, there is a correlation between fish ammonia output and the protein content of their diet, up to a certain point beyond which it makes no difference.
See figure 2:
Effects of dietary protein level on growth performance, carcass composition and ammonia excretion in juvenile silver perch
http/www.sciencedirect.com/science/article/pii/S0044848602001205

 
So, an algae eater, like a BN pleco, while "messy" may not actually have a large bioload, if by bioload we mean ammonia production?