Comment on Nitrate

[modified lung]

On 4/20/2022 at 8:33 PM, Patrick_G said:

So the Nitrate that forms in our tanks from fish waste or the compounds in liquid ferts are both N03-? 

Both are ultimately NO3-. The difference is the NO3- from fish waste beforehand is either something else and/or bound to something else until it's cleaved off by the metabolism of some microorganism(s) which can take up other valuable resources or possibly create other byproducts in the process.

I don't know a ton about plants but I imagine dosing straight NO3- would make everything much more efficient and bioavailable for plant uptake.

 

[CT_]

On 4/20/2022 at 8:33 PM, Patrick_G said:

So the Nitrate that forms in our tanks from fish waste or the compounds in liquid ferts are both N03-? 

yeah 🙂  one in the same.

[gardenman]

I suspect that fish that live in mountain streams where there's a nonstop supply of fresh, rushing water, from snow melt and runoff, have a lower tolerance for nitrates simply because it's not something they've ever experienced in the wild, so there's been no natural selection for nitrate tolerance. Fish that live in small pools/ponds, or slow moving, tannin rich water, might have developed a very high tolerance for nitrates as they've likely experienced very high nitrate levels and only those that survived it bred and reproduced.

What does all of that mean? It means there are no easy answers. If you want to grow plants, you need nitrates. Plants are living things that need food and nitrates are plant food. If you want a planted aquarium, you need nitrates. Do fish "need" nitrates? No. If you want a fish only tank, then you can keep nitrates at or near zero.  Will generations of fish bred and raised in a nitrate free tank be happy and healthy in other tanks with nitrates? Eh, probably not. There's been no selection for nitrate tolerance. If you're ever planning to sell or give away fish, you might want some level of nitrate tolerance bred into the fish.

There are discus breeders who raise their fish in RO water and RO water only with large water changes on a routine basis. There are other discus breeders who raise their fish in whatever water they have on hand and may not be as fanatical about water changes. Given a choice, I'd buy fish from the second breeder over the first. Why? His/her fish that survived are likely going to be genetically stronger than the fish that were raised in the RO water and never experienced anything but pristine water quality. Those susceptible to issues with water quality likely never survived long enough to reach a sellable size if raised in "normal" water. Any fish raised in pure RO water were never tested/stressed to see how they'd survive in more "normal" water.

As to the long-term effects on fish over ten years. Not a lot of our aquarium fish live ten years. The "typical" freshwater fish has a lifespan of less than ten years. Cory cats tend to live about five years. Most tetras come in at four or five years. Bettas live two to five years. (Bear in mind most bettas are a year or more old when bought as it takes that long for their finnage to mature.) For a "typical" fish keeper, the ten-year survival of their finned friends is at or near to zero. Not because of nitrates, but because they just don't live that long. It's like wanting to do a study on what happens to dogs over fifty years on a vegan diet. Well, no dog lives fifty years so you can't really study that.

[anewbie]

I believe one of the paper noted that temp impacted how nitrate affected fishes; and I would presume blindly that ph also has an impact; after all very low ph helps to neutralize ammonia (for example).

[anewbie]

Here is another interesting paper:

https://www.researchgate.net/publication/8063535_Nitrate_Toxicity_to_Aquatic_Animals_A_Review_With_New_Data_for_Freshwater_Invertebrates

--

Also i want to point out the first reference (which is not great) I found on my own but the other two was provided by folks on another forum. I feel obligated to give credit where it is due.

[nabokovfan87]

On 4/20/2022 at 7:19 AM, Minanora said:

I think the article was meant to be a guide for beginners best practice. Not so much an in depth read. Generally these articles are short enough that a beginner will read it in is entirety and gain enough information to help them keep a healthy aquarium. It provides information without bombarding them with data that is not really interesting to, or understandable by a beginner or non-nerm.

I think the last line of the blog post is pretty critical to keep in mind when reading the rest of the information.

A lot of new hobbyists might want to see 0-0-0 on their testing to "think" that their water has nothing but H2O in it's chemistry.  Step 1 is to understand the nitrogen cycle and why that matters.  Step 2 is to understand planted tanks and how that nitrogen can be used. 

The comment I made earlier about "where it comes from is pretty relevant" as well.  I think a lot of people want to deep dive into organic chemistry, and that's perfectly fine.  It matters for the health of the animal what the quality of the water is.  I specifically care if the nitrate is there because I'm not changing water enough, over feeding, or if it's because I'm adding it manually via dosing.  I use that as a metric because I need to know if the amount of water is being changed, how the plants are doing, how is their intake of the nitrogen day to day?

There's a lot of perspectives on this blog and on the organic chemistry side of things.  I won't say any of it isn't valuable, but that's how I view this when reading the blog and my own day to day issues with nitrates.

Edited April 21, 2022 by nabokovfan87

[anewbie]

On 4/21/2022 at 3:16 PM, nabokovfan87 said:

I think the last line of the blog post is pretty critical to keep in mind when reading the rest of the information.

A lot of new hobbyists might want to see 0-0-0 on their testing to "think" that their water has nothing but H2O in it's chemistry.  Step 1 is to understand the nitrogen cycle and why that matters.  Step 2 is to understand planted tanks and how that nitrogen can be used. 

The comment I made earlier about "where it comes from is pretty relevant" as well.  I think a lot of people want to deep dive into organic chemistry, and that's perfectly fine.  It matters for the health of the animal what the quality of the water is.  I specifically care if the nitrate is there because I'm not changing water enough, over feeding, or if it's because I'm adding it manually via dosing.  I use that as a metric because I need to know if the amount of water is being changed, how the plants are doing, how is their intake of the nitrogen day to day?

There's a lot of perspectives on this blog and on the organic chemistry side of things.  I won't say any of it isn't valuable, but that's how I view this when reading the blog and my own day to day issues with nitrates.

My problem with the blog is it suggested a value of nitrate that has been shown to be quite inappropriate to fishes. I believe that anything over 20ppm will have obvious long term health effect and 10ppm is prefer with lower being better for more delicate fishes. This article is suggesting that 80ppm is tolerable and I think that is just not a reasonable upper limit esp for larger more complex fishes. For stuff like guppies - well they are so heavily inbred for the most part they are not likely to have along cherish life regardless of water condition. But for anyone who keep wild fishes from soft water region you are probably going to want to keep nitrate below 5 ppm. And most cichild (angel fishes, oscar, ...) you should probably be trying to keep it below 10ppm with 20ppm an absolute cap. Of course most people probably don't expect their angel fishes to live 10 years or their cory 20 years so that there is that consideration.

[Widgets]

On 4/20/2022 at 8:06 PM, modified lung said:

It does say "10 mg NO3-N/L"

Nitrate-nitrogen (NO3-N) is a measurement of only the nitrogen (N) in nitrate (NO3). We have to multiply the NO3-N concentration by 4.43 to get the NO3 concentration.

So the 10 mg NO3-N/L = 44.3 mg NO3/L

As @modified lung pointed out, when reading the scientific papers we must be careful to know and understand what form(s) of Nitrogen they are testing and reporting. The 80ppm number referenced is equivalent to 18ppm in the scientific papers.

Also keep in mind that different species of fish will have different tolerances. There are some fish that live in pristine mountain streams where any wastes are quickly washed downstream, and there is not much upstream to be sending wastes down to them. There are some fish that live in areas that flood with the seasonal rains, but live in basically a mud puddle during the dry season. The native exposure to Nitrates varies with the location. There is no rule that applies to every fish, but you can make a general statement that applies to most fish. If you are keeping fish with specific needs, you need to understand and provide for those needs instead of the general statements. 

[anewbie]

On 4/22/2022 at 7:58 AM, Widgets said:

As @modified lung pointed out, when reading the scientific papers we must be careful to know and understand what form(s) of Nitrogen they are testing and reporting. The 80ppm number referenced is equivalent to 18ppm in the scientific papers.

Also keep in mind that different species of fish will have different tolerances. There are some fish that live in pristine mountain streams where any wastes are quickly washed downstream, and there is not much upstream to be sending wastes down to them. There are some fish that live in areas that flood with the seasonal rains, but live in basically a mud puddle during the dry season. The native exposure to Nitrates varies with the location. There is no rule that applies to every fish, but you can make a general statement that applies to most fish. If you are keeping fish with specific needs, you need to understand and provide for those needs instead of the general statements. 

Look at the last paper i referenced and it provides a bit more information. Also even given that 80ppm is nearly twice the value that the paper you mentioned where they were finding noticeable negative impact. I would argue that there is quite a bit of empirical data that shows values above 20ppm is harmful for many commonly kept fishes; though quantifying the harm level is a bit more difficult. 

[Guppysnail]

Again I’m not scientific but I’m just hoping to give you some peace of mind. My tap averages 25-35 nitrate.  My tanks run 20-40.  It’s hard even with gobs of plants both submerged and emergent to get below 20.  I’ve owned this house over 20 years and have kept fish most of that time with only minor breaks.  My fish of many variety’s spawn seem happy, healthy and I have experienced very few issues with any illnesses.  My fry both live bearing and hatched eggs do fine. I do believe the elevated nitrate is harmful but not at a level as a hobbyist I can see.  My fish and invertebrates appear to all have lifespans in accordance with what is reported as average lifespans. I know it’s not useable info but hope it sets your mind a ease. 

[Widgets]

On 4/22/2022 at 9:37 AM, anewbie said:

Look at the last paper i referenced and it provides a bit more information. Also even given that 80ppm is nearly twice the value that the paper you mentioned where they were finding noticeable negative impact. I would argue that there is quite a bit of empirical data that shows values above 20ppm is harmful for many commonly kept fishes; though quantifying the harm level is a bit more difficult. 

This paper? 

On 4/20/2022 at 6:23 PM, anewbie said:

2nd paper (which is better)

“Histopathological Changes and Zootechnical Performance in Juvenile Zebrafish (Danio rerio) Under Chronic Exposure to Nitrate”, António et. al.

From the summary on https://www.sciencedirect.com/science/article/abs/pii/S0044848616309115

A safety level of 100 mg L^-1 nitrate-N is recommended for rearing of juvenile zebrafish

A level of 100ppm nitrate-N is equivalent to 443ppm Nitrate from our test kits. I think a level of 80ppm is safe.

[anewbie]

On 4/22/2022 at 9:10 AM, Widgets said:

This paper? 

From the summary on https://www.sciencedirect.com/science/article/abs/pii/S0044848616309115

A safety level of 100 mg L^-1 nitrate-N is recommended for rearing of juvenile zebrafish

A level of 100ppm nitrate-N is equivalent to 443ppm Nitrate from our test kits. I think a level of 80ppm is safe.

This paper:

https://www.researchgate.net/publication/8063535_Nitrate_Toxicity_to_Aquatic_Animals_A_Review_With_New_Data_for_Freshwater_Invertebrates

[Widgets]

On 4/22/2022 at 1:08 PM, anewbie said:

This paper:

https://www.researchgate.net/publication/8063535_Nitrate_Toxicity_to_Aquatic_Animals_A_Review_With_New_Data_for_Freshwater_Invertebrates

From the summary

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). 

10ppm nitrate-N = 44.3 Nitrate in our test kits

Oncorhynchus mykiss = Rainbow trout

Oncorhynchus tshawytscha = Chinook salmon

Salmo clarki = Cutthroat trout

I don't know anyone keeping these in their aquariums, but this paper indicates that they are quite sensitive and can be negatively impacted by long term exposure to levels basically half of the generally accepted guidelines. Note that these fish are all stream dwellers that need pristine conditions. They would are some of the most sensitive species.

[anewbie]

On 4/22/2022 at 12:30 PM, Widgets said:

From the summary

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). 

10ppm nitrate-N = 44.3 Nitrate in our test kits

Oncorhynchus mykiss = Rainbow trout

Oncorhynchus tshawytscha = Chinook salmon

Salmo clarki = Cutthroat trout

I don't know anyone keeping these in their aquariums, but this paper indicates that they are quite sensitive and can be negatively impacted by long term exposure to levels basically half of the generally accepted guidelines. Note that these fish are all stream dwellers that need pristine conditions. They would are some of the most sensitive species.

I'm not sure but I would say that most SA cichlid (for example) also expect pristine waters.

[Widgets]

On 4/22/2022 at 1:48 PM, anewbie said:

I'm not sure but I would say that most SA cichlid (for example) also expect pristine waters.

I think you are getting hung up on the differences between a general rule, species specific information, and absolute statements. There are very few absolute statements. There can be many exceptions to general statements. Sometimes there are more exceptions than adherents to the general statement, but the general statement is useful to explain a concept without getting bogged down in the details of every species.

Using a general rule of an 80ppm upper limit and a 50% change to bring it down to 40ppm (assuming 0ppm source water) is useful to teach techniques that can then be extended to adapt to your specific conditions/requirements (25pp source water, or 10ppm species needs).

I can find several sources that will tell you to feed your fish once a day. That is a decent general rule. I can find species (or age ranges) that require several feedings every day. I can also find species that might only eat once a week or so. In nature, at times the food may be readily available for the fish to graze when they feel like it. Other times the food may be scarce and it is a feeding frenzy to got it while it is available. These differences may be seasonal and the changing conditions may induce breeding. Are the sources saying to feed once a day being irresponsible, or are they providing a useful general guideline?

It is the hobbyist's responsibility to research the fish that they are wanting to keep. Not only to understand the needed water parameters, but also to learn about behaviors, scaping preferences, and other special needs. It is also important to understand interaction with tank mates, and stocking levels (both supported by you tank, and species socialization. It would be nice to have sales associates knowledgeable in aquarium husbandry or nermology, but that is not always the case.

Edited April 22, 2022 by Widgets
Stupid typos

[anewbie]

On 4/22/2022 at 1:23 PM, Widgets said:

I think you are getting hung up on the differences between a general rule, species specific information, and absolute statements. There are very few absolute statements. There can be many exceptions to general statements. Sometimes there are more exceptions than adherents to the general statement, but the general statement is useful to explain a concept without getting bogged down in the details of every species.

Using a general rule of an 80ppm upper limit and a 50% change to bring it down to 40ppm (assuming 0ppm source water) is useful to teach techniques that can then be extended to adapt to your specific conditions/requirements (25pp source water, or 10ppm species needs).

I can find several sources that will tell you to feed your fish once a day. That is a decent general rule. I can find species (or age ranges) that require several feedings every day. I can also find species that might only eat once a week or so. In nature, at times the food may be readily available for the fish to graze when they feel like it. Other times the food may be scarce and it is a feeding frenzy to got it while it is available. These differences may be seasonal and the changing conditions may induce breeding. Are the sources saying to feed once a day being irresponsible, or are they providing a useful general guideline?

It is the hobbyist's responsibility to research the fish that they are wanting to keep. Not only to understand the needed water parameters, but also to learn about behaviors, scaping preferences, and other special needs. It is also important to understand interaction with tank mates, and stocking levels (both supported by you tank, and species socialization. It would be nice to have sales associates knowledgeable in aquarium husbandry or nermology, but that is not always the case.

I think we have to disagree here; I think 40ppm is already dangerously high for long term care and 80ppm is not reasonable for many common species of fishes kept in aquariums. If the concentration reaches 40ppm and is then lowered to 20 with the water change we can quibble - though i know people who think anything over 10ppm is unreasonably high; but I doubt few knowledge people - as a general rule - would agree that 80ppm is ok.

[Widgets]

On 4/22/2022 at 6:05 PM, anewbie said:

I think we have to disagree here; I think 40ppm is already dangerously high for long term care and 80ppm is not reasonable for many common species of fishes kept in aquariums. If the concentration reaches 40ppm and is then lowered to 20 with the water change we can quibble - though i know people who think anything over 10ppm is unreasonably high; but I doubt few knowledge people - as a general rule - would agree that 80ppm is ok.

One of the scientific papers you brought to the discussion indicated that 443ppm was a safe level for Zebra Danio. I have no scientific data to add to the discussion. Anything else is anecdotal.