Coronal Mass Ejection Carl
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Posts posted by Coronal Mass Ejection Carl
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23 minutes ago, MattyIce said:
80 for guppies seems reasonable.
Needs to be adjusted upwards for life stages older than fry and also because the Rubin 1977 study used potassium nitrate which is more toxic than sodium nitrate. Later papers put an asterisk by the KNO3 studies because they now know KNO3 is more toxic.
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13 minutes ago, MattyIce said:
Guppy - 836 ppm - 50% dead in 3 days
I wonder if those are fancy inbred 5 times over guppies, feeder guppies, or the cold water tolerant hearty guppies of the 60's and 70's.This is probably the guppy study she was referencing:
Pretty high numbers that would probably be even higher for older life stages.
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5 minutes ago, MattyIce said:
7 out of the 10 are 50% dead in 3 days. Is this supposed to be how much nitrates fish can get before a 50% mortality rate?
3 out of 8 in the 1,000 mg/L nitrate-N group in the Monsees study died. That's 37.5% in ~30 days.
96-hour LC50 where half die after 4 days is probably going to be higher. One way to determine what chronic exposure level would be tolerable is to take 10% of that value.
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30 minutes ago, MJV Aquatics said:
I dunno, opposing arguments in a public forum would seem to meet the definition. Then again. there's no point in beating a dead horse...but you gotta ask why anyone defends pollution?
Why doesn't everyone do two 90% water changes per day like some discus keepers?
You don't do two 90% water changes per day? You're defending pollution.
Did you not put on sunscreen to get the mail? You're defending skin cancer.
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1 hour ago, Connor Elliott said:
I just wanted to know how to read a test kit 😂
The good news is that you basically don't have to test nitrate. And you don't have to worry about 20 vs. 40 or even 80 ppm. They are all equally non-toxic.
You know who Diana Walstad is? Well...
And this was before even better studies came out.
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13 minutes ago, MJV Aquatics said:
Like I said, the debate is over. 🙂
I accept your concession.
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2 hours ago, MattyIce said:
Nitrate bonds with Hemoglobin to create Methoglobin which can no longer carry oxygen. This causes low oxygen concentrations in the fishes blood,(Human Blood, Livestock Blood, ect) requiring the fish to inhale more oxygen.
in the study below, it found at around 100 ppm nitrate, oxygen was consumed at 3 times the rate with water at 0 nitrates.https://academic.oup.com/conphys/article/8/1/coz092/5658492
While not completely analogous, it seems like climbing mount Everest, where the higher one goes/ the higher the nitrates go, the less oxygen is able to be used.
Having to take a breath more often than you are used to 24/7/365, the stress of that can't be good.Ah, yes, the old Isaza article.
That paper states that:
QuoteNitrate enters the body via passive diffusion across the gills and results in the endogenous conversion of nitrate to nitrite (Camargo et al., 2005; Monsees et al., 2017), which then causes methaemoglobin formation.
Which is interesting because the Monsees paper doesn't say that at all. Monsees is a pivotal paper in nitrate toxicity research because it finally answers the question of how nitrate gets into fish:
QuoteUntil today, the uptake of nitrate is still poorly understood, mainly due to the fact that most tissues represent a barrier preventing the passage of the large hydrated nitrate ion. In their study on nitrate toxicity to African catfish (Clarias gariepinus), Schram, Roques, Abbink, et al. (2014) concluded that the integument of the fish forms a significant barrier to waterborne nitrate. As a consequence, alternative routes for nitrate uptake are limited and uptake via the gills seems most plausible with regard to the direct contact with the ambient water as well as the importance in osmoregulation and ion uptake (Hwang 2009). However, a low permeability for nitrate through the gills was discussed in trout (Stormer et al. 1996) and has been reported in freshwater crayfish (Jensen 1996). In contrast, nitrite uptake has been described for the gills as well as the intestinal wall. For example, Grosell and Jensen (2000) documented nitrite passage over the intestinal/stomach wall of the European flounder and nitrite uptake in the stomach is very fast in rats (Bryan, Fernandez, Bauer, Garcia-Saura, Milsom, Rassaf, Maloney, Bharti, Rodriguez & Feelisch 2005). Additionally, nitrite and chloride compete for the active branchial chloride uptake mechanism in freshwater fish (Williams & Eddy 1986), and as the chloride concentration in freshwater is low, the presence of nitrite can lead to massive nitrite accumulation in the plasma (Grosell & Jensen 2000). Furthermore, low stability of nitrite suggests rather acetic conditions to prevent fast oxidation.
Consequently, we hypothesized that uptake involves a reduction of nitrate to nitrite in the stomach, prior to the actual passage of the intestinal wall. Such route would result in high plasma nitrite, similar to those observed here. Therefore, we assessed the reduction of nitrate to nitrite in stomach juice in an in vitro experiment. We demonstrate that nitrate is rapidly converted into nitrite reaching a maximum of 74 lMNO?2 after 90 min. Our findings strongly indicate that conversion of nitrate to nitrite in the gastrointestinal system of tilapia represents the most probable uptake route. As a consequence, nitrate toxicity in tilapia is mainly a result of nitrate reduction to nitrite and irreversible oxidation of haemoglobin to methaemoglobin.
In the early days, scientists thought it could be through the gills since a lot of ions pass or are transported through them. But later studies found that gills were fairly impermeable to nitrate which left them wondering what alternative routes could there be.
Isaza also cites Camargo which is just a review paper that I don't believe performed any experiments. It mentions branchial permeability twice:
QuoteThe main toxic action of nitrate on aquatic animals is due to the conversion of oxygen-carrying pigments (e.g., hemoglobin, hemocyanin) to forms that are incapable of carrying oxygen (e.g., methemoglobin) (Grabda ct al., 1974; Conrad, 1990; Jensen, 1996; Scott and Crunkilton, 2000; Cheng and Chen, 2002). Nevertheless, owing to the low branchial permeability to nitrate, the NO3 uptake in aquatic animals seems to be more limited than the uptake of NHt and NO2, contributing to the relatively low toxicity of nitrate (Russo, 1985; Meade and Watts, 1995; Jensen, 1996; Stormer et al., 1996; Cheng and Chen, 2002; Alonso and Camargo, 2003).
QuoteJensen (1996) studied the uptake and physiological effects of nitrate ions (from NaNO3) in the freshwater crayfish Astacus astacus. The nitrate uptake was minor in crayfish exposed to a nitrate concentration of 14 mg NO3-N/l for seven days, indicating a low branchial permeability to nitrate (Table I). This minor uptake of nitrate appeared to be passive, the haemolymph nitrate concentration staying far below the ambient nitrate concentration. In addition, nitrate exposure did not induce significant changes in haemolymph chloride, sodium or potassium concentrations, nor in divalent cations and anions, extracellular osmolality and amino acid concentrations (Table 1).
Both of those studies are pre-Monsees so it likely never occurred to them to consider incidental ingestion. Regardless, they failed to control for it so they can't legitimately conclude that any nitrate uptake, however minor, was via the gills.
So, basically, Isaza cites Monsees as support for branchial uptake when in fact Monsees concludes it's not branchial uptake. Then it indirectly references two old studies that didn't consider and prevent incidental ingestion.
And in its own experiments, Isaza makes the same mistake. This is on top of the fact that the alleged branchial uptake only occurred when the fish were exposed to extreme pH levels.
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6 minutes ago, MJV Aquatics said:
Lets get real here....What I said was that fry raised in FRESH, CLEAN water grow faster and larger and are healthier. I bred, raised, and sold over 300 fish last year - how about you?
Anybody can do that. It doesn't make you an authority on the subject. Have you kept track of the lifespans of the fish you sold? Do they live longer than breeders who change water less frequently?
6 minutes ago, MJV Aquatics said:Out of context, 150ppm nitrates may be fatal for some fish. I'm not going to continue to debate the merits of fresh, clean water with you. Quibbling over nitrate number values seems pretty pointless to me. 🙂
Really? Which fish? Scientific evidence required.
I have provided scientific evidence. All you have is an opinion.
You still haven't answered my previous points:
A lot of those studies are for establishing discharge limits in natural waters. Not to mention there are a few on fathead minnows, guppies, and gamefish.
Age in fish isn't just related to years but growth rate and size. A fish that's grown rapidly to market size is chronologically young but biologically older as it's at the point where feed conversion ratio drops and it's no longer economical to keep growing them. Anything that doesn't manifest in those eight months probably isn't ever going to manifest.
Growing fish fast and big shortens their chronological lifespans so I don't know if this is really a good measure of success. What fish farms and hobbyists do isn't any different.
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15 minutes ago, MJV Aquatics said:
Too many 'hobbyists' seem to not want to do partial water changes so they wish to believe that expert advice about low nitrates just isn't real.
The vet at UC Davis told me that <150 ppm was fine but what do they know they only take care of the exhibits in public aquariums and aren't "experts."
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12 minutes ago, MJV Aquatics said:
I disagree. Fish may tolerate poor water quality for months, but it may shorten their lives by years. Studies on farmed fish can never reveal that.
A lot of those studies are for establishing discharge limits in natural waters. Not to mention there are a few on fathead minnows, guppies, and gamefish.
Age in fish isn't just related to years but growth rate and size. A fish that's grown rapidly to market size is chronologically young but biologically older as it's at the point where feed conversion ratio drops and it's no longer economical to keep growing them. Anything that doesn't manifest in those eight months probably isn't ever going to manifest.
Growing fish fast and big shortens their chronological lifespans so I don't know if this is really a good measure of success. What fish farms and hobbyists do isn't any different.
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7 hours ago, MJV Aquatics said:
I don't think we can trust studies done on farmed fish because they'll be in the freezer or on the table long before they reach their full life span.
A lot of those studies are for establishing discharge limits in natural waters. Not to mention there are a few on fathead minnows, guppies, and gamefish.
7 hours ago, MJV Aquatics said:It's long been held that high nitrates lowers fish immune systems and shortens life spans in aquarium fish.
There's no scientific evidence of this though. And age in fish isn't just related to years but growth rate and size. A fish that's grown rapidly to market size is chronologically young but biologically older as it's at the point where feed conversion ratio drops and it's no longer economical to keep growing them. Anything that doesn't manifest in those eight months probably isn't ever going to manifest.
7 hours ago, MJV Aquatics said:With over 50+ years in the hobby, I've found that the very highest water quality yields the fastest growing fry, and the largest, healthiest fish with the best vigor and color.
Growing fish fast and big shortens their chronological lifespans so I don't know if this is really a good measure of success. But it is exactly what fish farms try to do...
7 hours ago, MJV Aquatics said:The greatest success in the hobby comes with the highest possible water quality. 🙂
What is water quality? Why are we focused on nitrate which is only one of three nutrient cycles? Cleaning filters might actually be more important than changing water.
A lot of people do leave the hobby and I think the peer pressure over nitrates and water changes is part of it.
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1 minute ago, GardenStateGoldfish said:
I saw a study of rainbow trout kept at 10 ppm nitrate and another batch kept at 100 ppm nitrate and there was no difference in health, I am neutral on the issue, my boss never changes water in his tank (yikes!) and I tested his nitrates one time and they were like 300 or something crazy, all his fish were fine he never has any disease or anything and they don't show signs of stress, he also adds new fish without an issue, they don't go into shock.
That being said, I have plenty of friends who swear that over 40 nitrate causes damage, so I just do water changes at 40 ppm nitrate or if my PH starts to drop (I have really hard water, but lower in KH) Usually do a change every weekend or every two weeks because I enjoy taking care of the tanks anyway.
Nitrate is probably not the only thing that can become an issue in old tank syndrome, so I do still recommend doing water changes unless your an expert that knows how iron levels or phosphate levels or whatever else is in the water will impact your tank.Yeah, it's actually 44.3 vs. 443 mg/L nitrate once you convert the units. For 8 months. I don't think anyone is hitting 400+ for months on end.
I'm now actually more concerned about dissolved organic carbon:
https://www.sciencedirect.com/science/article/abs/pii/0144860988900064
It takes around 1,000 mg/L nitrate-nitrogen to inhibit growth in tilapia. Here, levels of DOC 125 times less were doing it. Not to mention there's a strong correlation between organic waste and disease but not with nitrate.
The control group in this study experienced spontaneous denitrification hence the low nitrate value.
What I'm afraid of is that organic waste trapped in filters/substrate continuously break down and release DOC and frequent filter cleanings, not water changes, are needed.
That means that people doing water changes every week and cleaning filters twice a year have it backwards.
It requires several thousand dollars of equipment to test DOC so it's going to be awhile before better technology lowers prices.
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3 hours ago, CT_ said:
Ok yeah then lets say 8000 is surly toxic.
Someone posted a study here showing 40 significantly hindered growth for something common (I forget which fish). All I know is what people have said and what literature I've read. I'm sure it depends on species too.
There just isn't scientific evidence to support the hobby's 40 ppm recommendation.
3 hours ago, CT_ said:I decided to do more reading and it looks like young fish and inverts are especially sensitive. Some have an LC50 10's of nitrate and low percentage LC in the 1's. I guess it's all very species dependent.
This has some good tables but its mostly for juveniles and younger. https://www.waterboards.ca.gov/water_issues/programs/tmdl/records/region_2/2008/ref2426.pdf
Amphibians and some invertebrates seem to be more sensitive. There's a dramatic difference based on life stage though. Eggs and larvae/fry are the most sensitive. The papers discussing where to set discharge limits have to consider the most vulnerable life stage and species since they have an entire food chain to protect. Young life stages don't produce enough methemoglobin reductase that reverses the effects of nitrite in the blood (fish swallow nitrate-laden water which is then converted to nitrate in the digestive tract).
That Camargo paper is usually the first that Google spits out. It relies on the discredited Kincheloe 1979 study for some of its lowest numbers. Later studies attempted to replicate the results but the numbers they got were several magnitudes larger.
https://pubmed.ncbi.nlm.nih.gov/16916038/
3 hours ago, darkG said:Here are some findings:
This seems like a good time to point out that nitrate-nitrogen is nitrate * 4.43 so if the EC20/LC20 for a particular species is 1,000 mg/L nitrate-N it's 4,430 mg/L nitrate. EC20/LC20 should be lower than LC50 so the acute toxicity levels for fish are in the >4,000 mg/L nitrate range. No normal aquarium is going to subject fish to a chronic level of nitrate 10% of that. And you can see why fussing about 20 vs. 40 ppm isn't important.
2 hours ago, Daniel said:I am pretty full of myself most days, but I would think twice before I got into a discussion with @Coronal Mass Ejection Carl about nitrates. I think he buys them by the barrel load.🙂
I've spent more time reading nitrate toxicity papers than studying for graduate level courses. It's become a hobby now and every few weeks I search for any new papers on nitrate or oxygenation.
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53 minutes ago, CT_ said:
Some say >20 is bad for sensitive critters like shrimp and some fish. I have no way of knowing if that's right though.
Also to be pedantic (sorry) toxic is a matter of dose not substance. 80+ nitrate for example is probably toxic, 10 is probably not.
There are plenty of scientific studies on nitrate toxicity. The 96-hr LC50s are in the 4,000-8,000 ppm range. Ten percent of that is considered OK for chronic exposure. And indeed salmon have been kept at 443 ppm for 8 months with no ill effects (they even performed blood work on them).
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Nitrate is so non-toxic that you basically don't have to test let alone worry about 20 vs. 40 ppm.
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Excel is the primary suspect. It's fish poison, after all.
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1 hour ago, madmark285 said:
You seem to be knowledgeable on this topic so I ask.
Concerning the $60 portable Hanna meter, why do they have a specific machine for each type of test? Why not a single device with a switch which can read nitrites, Ph, ammonia, etc? Is this an engineering issue or a regulation issue ie: prevent user error. Or just an marketing ploy.
For the consumer aquarium market, there may be a high demand for a $60 multipurpose colorimeter.
Any opinions?
Hanna does make multiparameter meters but they're expensive ($1,000). Other manufacturers make them as well so it's certainly possible.
It's probably just cheaper/easier to make individual meters. And people can save money buying only the ones they need.
One thing I don't like about Hanna is that they use the Nessler ammonia method which no one uses anymore.
Also, Hach's chromotropic acid method for nitrate is probably the cheapest accurate and reliable nitrate test.
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Nitrofuran is said to be unstable in water and also photosensitive.
Kanamycin is apparently stable in water hence the every 3 day dosing.
There's also microbial degradation. For example, bacteria will consume sodium thiosulfate. I'm not sure about other dechlorinating chemicals but I wouldn't be surprised.
You can find studies or data on the persistence of most chemicals in aquatic environments thanks to all the environmental pollution research.
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Nitrate isn't volatile.
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When I deep clean I remove bio media from the tank. The times I put the media (plus a bunch of gunk) in a bucket the dissolved oxygen levels dropped pretty fast.
YMMV, of course.
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15 hours ago, Schwack said:
Of these, the one I'd want the most is a nitrate colorimeter calibrated to the API kit. I can't tell 20 from 40 from 100. I've got reference images and such, but it's all basically just RED. I'd spend $50 to get an accurate nitrate reading without hesitation. Looks like the Hanna Instruments model is only for marine aquaria though.
Nitrate is so non-toxic that being able to distinguish between 20, 40 and 100 isn't necessary. I don't even test for nitrate because I would have to stop changing water for months to reach toxic levels.
Organic carbon, on the other hand, is much more dangerous and appears to require frequent filter cleanings to control. Water changes alone are probably insufficient.
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10 hours ago, FishyThoughts said:
The product I want is a digital water tester that could test all parameters/nutrients of the water. And was accurate without requiring constant calibration.
Most current sensor tech requires calibration every 1-2 hours (ammonia, nitrate). Nitrite sensors are quite rare and it seems only one company makes them.
The three ammonia standard solutions required for calibration can be contaminated by atmospheric ammonia.
There's always research on new sensor technology and truly reagent-less sensors for aquariums will probably be available in a few decades.
There's also colorimeter/spectrophotometer technology which uses a machine eye to read colorimetric tests. That you can get now. It doesn't require frequent calibration.
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On 1/29/2021 at 5:58 PM, Tory said:
Someone else might've said this (I didn't read all 15 pages of comments lol) but my dream product would be a full test kit that's the equivalent of a digital pregnancy test. So instead of trying to decipher the colors it just reads digitally as "0ppm ammonia, 0ppm nitrites, 20ppm nitrates" etc
https://www.hach.com/colorimeters/dr900-colorimeter/family?productCategoryId=35547203827
Cheaper on eBay especially older models like the 890 which can perform all the same tests but just doesn't have USB and automatic logging of results.
6 hours ago, madmark285 said:A general purpose and affordable colorimeter for the API Master test kit. Hanna Instruments makes specific instruments for nitrates, phosphate, nitrites, etc, a single colorimeter designed specific for the API Master test kit would be great!
I am color blind but I can see the different colors produced by the tests, I just struggle with slight variation of colors for low level readings.
What I currently do, test my tap and aquarium water and compare the colors in the test tubes.
https://iorodeo.com/products/educational-colorimeter-kit?variant=12262607558
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Columnaris is everywhere. Even if you managed to completely eliminate it from your tank your new fish will reintroduce it.
Question about Nitrates
in General Discussion
Posted
Other weirdness in the Rubin study:
Their ammonia LC50s are quite high. It's total ammonia but the pH isn't that low. I wouldn't expect ammonia and nitrate LC50s to be that close.