Acceptable Nitrate Levels.
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Phreaker
New Member
Yes, experts do tell us nitrates weaken the immune system, cause hematological changes, negatively impact reproduction.
The issue is that, the concentrations of nitrate that do cause such significant changes are A LOT higher than the 20 or 40 or whatever ppm.
I do not count random websites on google as being experts, especially when they provide no evidence for what they are saying.
The issue is that, the concentrations of nitrate that do cause such significant changes are A LOT higher than the 20 or 40 or whatever ppm.
I do not count random websites on google as being experts, especially when they provide no evidence for what they are saying.
From human medical literature/research, there are some inherent problems in constructing a research study that can be used to draw conclusions from. In humans,there are so many simultaneous confounding variables that the doses of your compound of interest have to be huge (relatively speaking) to see a meaningful effect. Hence why population sizes for phase 3 trials need to be so much larger than phase 1 trials for example, etc.
I think fish experimental design probably has some of these same real-world issues. You have to have concentrations large enough to poison the fish because your grant is only funding you for 6 months of work, not for observing the fish over 5 years for example. Then as a scientist you draw some kind of extrapolation from there, like "10min at 400ppm is lethal, 2 weeks at 100 ppm is lethal, etc". I think when you get to lower concentrations, it's a lot harder to say what is true effect and what is circumstantial, and as a result experiments with 20 and 40 ppm are just so much harder to design. Plus, with the fact that there probably isn't great funding for that type of research, it probably leaves it up to us to try and interpret the existing scientific evidence as best we can.
I think science has really advanced many fields in the past 20 years, but laypeople who are interested in "using science" need to also have some level of understanding of the limitations of the scientific method, and just because an experiment hasn't been able to show something doesn't always mean it's conclusive, it could have also been just inadequately designed.
I think fish experimental design probably has some of these same real-world issues. You have to have concentrations large enough to poison the fish because your grant is only funding you for 6 months of work, not for observing the fish over 5 years for example. Then as a scientist you draw some kind of extrapolation from there, like "10min at 400ppm is lethal, 2 weeks at 100 ppm is lethal, etc". I think when you get to lower concentrations, it's a lot harder to say what is true effect and what is circumstantial, and as a result experiments with 20 and 40 ppm are just so much harder to design. Plus, with the fact that there probably isn't great funding for that type of research, it probably leaves it up to us to try and interpret the existing scientific evidence as best we can.
I think science has really advanced many fields in the past 20 years, but laypeople who are interested in "using science" need to also have some level of understanding of the limitations of the scientific method, and just because an experiment hasn't been able to show something doesn't always mean it's conclusive, it could have also been just inadequately designed.
AbbeysDad
Fish Gatherer
Arsenic is a poison - do we need to know exactly how much will kill us, to know that any amount is bad? (well, perhaps the 'unsub's' among us do!)
Perhaps another analogy would be to question how much air pollution is okay for us to breathe? Or why are there EPA limits on nitrates in our drinking water?
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Although not as toxic as ammonia and nitrite, nitrates are a poison. The purest water will not have nitrates, phosphates, pheromones, and heavy metals and will have the appropriate amounts of calcium and magnesium.
In nature, rains and snow melt results in an endless supply of fresh water. Did you know that the flow of the Amazon river is so great that fresh water can be collected 12 miles out at sea?!
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In the closed aquarium system, it's up to us to supply fresh water to flush out the pollution. I've been in the hobby 50+ years and in the old days we thought a 20-25% weekly water change was plenty regardless of stock level. Then, in time we got smarter. Professional breeders quickly learned that fry grew faster and more robust with fresh, pure water. They instituted auto water change systems of around 25% daily or flow through systems so fresh water is introduced continuously...and this is often in addition to far advanced filtration systems that most hobbyist would be in awe of.
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So all things considered, do we really need a precise number for us to know that pollution (aka nitrates+evil) is really bad for fish. Or might we just relax and resign ourselves that clean, fresh water is better than polluted water.
Perhaps another analogy would be to question how much air pollution is okay for us to breathe? Or why are there EPA limits on nitrates in our drinking water?
---
Although not as toxic as ammonia and nitrite, nitrates are a poison. The purest water will not have nitrates, phosphates, pheromones, and heavy metals and will have the appropriate amounts of calcium and magnesium.
In nature, rains and snow melt results in an endless supply of fresh water. Did you know that the flow of the Amazon river is so great that fresh water can be collected 12 miles out at sea?!
---
In the closed aquarium system, it's up to us to supply fresh water to flush out the pollution. I've been in the hobby 50+ years and in the old days we thought a 20-25% weekly water change was plenty regardless of stock level. Then, in time we got smarter. Professional breeders quickly learned that fry grew faster and more robust with fresh, pure water. They instituted auto water change systems of around 25% daily or flow through systems so fresh water is introduced continuously...and this is often in addition to far advanced filtration systems that most hobbyist would be in awe of.
---
So all things considered, do we really need a precise number for us to know that pollution (aka nitrates+evil) is really bad for fish. Or might we just relax and resign ourselves that clean, fresh water is better than polluted water.
Phreaker
New Member
We seem to be going on a tangent here.
Clinical trials have huge population sizes in order to evaluate whether the drug works, and for how long, while also making sure the side effects are known and which individuals should or should not use it.
These studies are not creating fish medicine, they are testing whether a substance is acutely and/or chronically toxic to fish. This is a much simpler experiment, and besides, any 'confounding variables' would be more likely to make nitrate appear more toxic than less. ( There are more things that can kill fish than things that would save them from nitrate toxicity.)
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Yes, the biggest limitation of the chronic studies is the timeframe, fortunately these scientists based their conclusions on more than 'X ppm is lethal' for the chronic experiments. They observed changes to blood plasma, the liver as well as behaviour among other things. Infact, for the more reasonable concentrations, none of the fish actually died. "No mortality was registered in fish exposed up to 200 mg L−1 nitrate " (880ppm NO3-) however, the conclusion was not that 880ppm is fine because no fish died. "Except for the lowest nitrate concentration (100 mg L−1 nitrate-N), the histological survey revealed significant changes induced by nitrate in all examined organs...". (440ppm NO3-). Even though no fish died at 880ppm, they observed negative histological changes, compared to the control group with no nitrate.
It would be logical to assume fish at over 440ppm would have significantly shorter lifespans as the histological changes / injuries to organs would likely lead to an earlier death.
But, after looking at the study it would seem illogical to interpret data showing no significant histological changes at 440ppm nitrate as stating, nitrate must be kept below 20ppm.
What is such an interpretation based on?
Clinical trials have huge population sizes in order to evaluate whether the drug works, and for how long, while also making sure the side effects are known and which individuals should or should not use it.
These studies are not creating fish medicine, they are testing whether a substance is acutely and/or chronically toxic to fish. This is a much simpler experiment, and besides, any 'confounding variables' would be more likely to make nitrate appear more toxic than less. ( There are more things that can kill fish than things that would save them from nitrate toxicity.)
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Yes, the biggest limitation of the chronic studies is the timeframe, fortunately these scientists based their conclusions on more than 'X ppm is lethal' for the chronic experiments. They observed changes to blood plasma, the liver as well as behaviour among other things. Infact, for the more reasonable concentrations, none of the fish actually died. "No mortality was registered in fish exposed up to 200 mg L−1 nitrate " (880ppm NO3-) however, the conclusion was not that 880ppm is fine because no fish died. "Except for the lowest nitrate concentration (100 mg L−1 nitrate-N), the histological survey revealed significant changes induced by nitrate in all examined organs...". (440ppm NO3-). Even though no fish died at 880ppm, they observed negative histological changes, compared to the control group with no nitrate.
It would be logical to assume fish at over 440ppm would have significantly shorter lifespans as the histological changes / injuries to organs would likely lead to an earlier death.
But, after looking at the study it would seem illogical to interpret data showing no significant histological changes at 440ppm nitrate as stating, nitrate must be kept below 20ppm.
What is such an interpretation based on?
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Phreaker
New Member
@AbbeysDad I am not suggesting we let our tanks get to 3 figure nitrate ppm, I am also not the one looking for a precise number. Many others seem to have the precise number of ' always below 20ppm'.
My entire point is to not have this precise number, it over complicates an already over complicated hobby. Whenever some new user asks for help and posts their water parameters, there is always someone screeching about their 22ppm nitrate being too high.
It is certainly useful to draw the line somewhere, when advising others. Perhaps 20ppm is not where this line should be.
My entire point is to not have this precise number, it over complicates an already over complicated hobby. Whenever some new user asks for help and posts their water parameters, there is always someone screeching about their 22ppm nitrate being too high.
It is certainly useful to draw the line somewhere, when advising others. Perhaps 20ppm is not where this line should be.
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Nitrates are similar to nitrites. Nitrites are poisonous to fish and all animals and have been linked to cancers in people and animals. It may also cause cancer in fish, if the fish live long enough to develop them. Unfortunately most fish die within a few days of exposure to nitrites and monitoring them for cancers is not able to occur. The fact low levels of nitrites kill fish, would suggest nitrates also harm and potentially kill fish.
Nitrates also harm people and animals and possibly cause cancer in people and animals that regularly ingest water containing high levels of nitrates. The World Health Organisation has suggested people avoid drinking water containing nitrates, and medical professionals around the world are pushing for nitrites to be removed from food.
Prior to the 1950s, cancer was relatively unheard of and although some people developed it, it was rare. Now they estimate one in three people will develop cancer. What has changed in the last 70 years? An increase in chemicals in the environment, food and water supply. Nitrites and subsequently nitrates by association, are linked to cancer in people and animals, and fish are affected by them too.
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Ammonia, nitrite and nitrate are not found in natural ecosystems in any measurable amount, which means fish and other aquatic lifeforms (besides bacteria) never evolved to deal with them. Ammonia is produced by fish in the wild but it is diluted by the water and used by phytoplankton, multi-celled algae and higher plants. If any is left after the plants have used their share, it would also be broken down by aerobic bacteria living on the rocks and substrate. Any nitrates would be broken down by anaerobic bacteria living in the mud or inside large porous rocks. But fish in the wild are not exposed to any levels of ammonia, nitrite or nitrate like what is found in aquariums. This is based on my own water testing that I did when out collecting fish from the wild (in fresh and marine environments), and from other people who also collect fish and test the water at the site where the fish are found. Ammonia, nitrite and nitrate levels in these areas are always 0ppm.
Ammonia is also washed away from the fish by flowing water in creeks and rivers, and the number of fish vs volume of water in the wild is significantly different to aquariums. In the wild 1 inch of fish might have 1000+ litres (250 gallons) of water, (oceanic fishes will have more water per fish). This might increase during the wet season due to rainfall increasing the water level in rivers, and it might decrease during the dry season as water evaporates. In an aquarium, some books and websites suggest 1 inch of fish per gallon (4 litres) of water.
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When I was working in the pet industry, we had numerous customers come in asking for help. Some had diseases in their tanks and other just had poor water quality. We regularly had customers come in saying they had lost most of their fish over a period of time and didn't know why. When we tested their tank water, it had really high nitrate levels (in excess of 100ppm). Their ammonia and nitrite levels were 0ppm, and their pH was usually below 5.0. They didn't do water changes and simply topped up their tanks.
Some of these customers had bought fish from the same batches we had in our display tanks, and the fish in our display tanks were fine and none had died. The main difference between the customer's fish and the ones in the display tanks was the high nitrate and low pH. Some of the fish were tetras and we ruled out pH because those fishes were naturally found in acid water. This left nitrate as the main reason for the unexplained fish deaths.
We told the customers to start doing small water changes & gravel cleans, and to increase the volume they changed over time. We also got them to clean their filter every month because most of them had not cleaned their filters in 6 months or more. Some tanks had been set up for several years, never had a water change and never had their filter cleaned. The customers started doing small water changes and gravel cleans, and cleaned their filters, and the random deaths stopped and they had no more problems like that.
Whilst we didn't have the fish necropsied and tested under lab conditions, we found that keeping nitrates low by doing regular water changes, gravel cleaning and filter cleaning, helped reduce the number of unexplained fish deaths in aquariums and significantly fewer disease outbreaks.
The shops I worked at had lots of repeat customers who regularly brought in new customers to get help from us, and most of them did extremely well with their fish after we had helped them with their issues. Many of our customers also started breeding fish in their aquariums and had small fish like neon tetras live for 4 or 5 years, and some had angelfish that were 8-10 years old. Prior to these customers taking advice from us, most of them were happy if any of their fish lived for 6 months.
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Over the years my fish keeping experiences (both good and bad), have lead me to the conclusions that big regular water changes, regular gravel cleaning, and regular filter cleaning helps keep fish alive for a lot longer. And keeping ammonia and nitrite levels at 0ppm at all times, and nitrate levels as low as possible goes a long way to having fish that live for many years and not die after just a few months.
There have been articles I have read in science and fish magazines over the years. These articles have supported my own experiences and the consensus is to try and keep nitrates as close to 0ppm as possible at all times. I work on keeping them under 20ppm, however for some people this is not always possible due to the nitrates in their tap water. But we should be trying to keep the water as close to what it is in the wild, with a stable pH and GH, and 0 ammonia, 0 nitrite and 0 nitrate.
Nitrates also harm people and animals and possibly cause cancer in people and animals that regularly ingest water containing high levels of nitrates. The World Health Organisation has suggested people avoid drinking water containing nitrates, and medical professionals around the world are pushing for nitrites to be removed from food.
Prior to the 1950s, cancer was relatively unheard of and although some people developed it, it was rare. Now they estimate one in three people will develop cancer. What has changed in the last 70 years? An increase in chemicals in the environment, food and water supply. Nitrites and subsequently nitrates by association, are linked to cancer in people and animals, and fish are affected by them too.
---------------------
Ammonia, nitrite and nitrate are not found in natural ecosystems in any measurable amount, which means fish and other aquatic lifeforms (besides bacteria) never evolved to deal with them. Ammonia is produced by fish in the wild but it is diluted by the water and used by phytoplankton, multi-celled algae and higher plants. If any is left after the plants have used their share, it would also be broken down by aerobic bacteria living on the rocks and substrate. Any nitrates would be broken down by anaerobic bacteria living in the mud or inside large porous rocks. But fish in the wild are not exposed to any levels of ammonia, nitrite or nitrate like what is found in aquariums. This is based on my own water testing that I did when out collecting fish from the wild (in fresh and marine environments), and from other people who also collect fish and test the water at the site where the fish are found. Ammonia, nitrite and nitrate levels in these areas are always 0ppm.
Ammonia is also washed away from the fish by flowing water in creeks and rivers, and the number of fish vs volume of water in the wild is significantly different to aquariums. In the wild 1 inch of fish might have 1000+ litres (250 gallons) of water, (oceanic fishes will have more water per fish). This might increase during the wet season due to rainfall increasing the water level in rivers, and it might decrease during the dry season as water evaporates. In an aquarium, some books and websites suggest 1 inch of fish per gallon (4 litres) of water.
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When I was working in the pet industry, we had numerous customers come in asking for help. Some had diseases in their tanks and other just had poor water quality. We regularly had customers come in saying they had lost most of their fish over a period of time and didn't know why. When we tested their tank water, it had really high nitrate levels (in excess of 100ppm). Their ammonia and nitrite levels were 0ppm, and their pH was usually below 5.0. They didn't do water changes and simply topped up their tanks.
Some of these customers had bought fish from the same batches we had in our display tanks, and the fish in our display tanks were fine and none had died. The main difference between the customer's fish and the ones in the display tanks was the high nitrate and low pH. Some of the fish were tetras and we ruled out pH because those fishes were naturally found in acid water. This left nitrate as the main reason for the unexplained fish deaths.
We told the customers to start doing small water changes & gravel cleans, and to increase the volume they changed over time. We also got them to clean their filter every month because most of them had not cleaned their filters in 6 months or more. Some tanks had been set up for several years, never had a water change and never had their filter cleaned. The customers started doing small water changes and gravel cleans, and cleaned their filters, and the random deaths stopped and they had no more problems like that.
Whilst we didn't have the fish necropsied and tested under lab conditions, we found that keeping nitrates low by doing regular water changes, gravel cleaning and filter cleaning, helped reduce the number of unexplained fish deaths in aquariums and significantly fewer disease outbreaks.
The shops I worked at had lots of repeat customers who regularly brought in new customers to get help from us, and most of them did extremely well with their fish after we had helped them with their issues. Many of our customers also started breeding fish in their aquariums and had small fish like neon tetras live for 4 or 5 years, and some had angelfish that were 8-10 years old. Prior to these customers taking advice from us, most of them were happy if any of their fish lived for 6 months.
---------------------
Over the years my fish keeping experiences (both good and bad), have lead me to the conclusions that big regular water changes, regular gravel cleaning, and regular filter cleaning helps keep fish alive for a lot longer. And keeping ammonia and nitrite levels at 0ppm at all times, and nitrate levels as low as possible goes a long way to having fish that live for many years and not die after just a few months.
There have been articles I have read in science and fish magazines over the years. These articles have supported my own experiences and the consensus is to try and keep nitrates as close to 0ppm as possible at all times. I work on keeping them under 20ppm, however for some people this is not always possible due to the nitrates in their tap water. But we should be trying to keep the water as close to what it is in the wild, with a stable pH and GH, and 0 ammonia, 0 nitrite and 0 nitrate.
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Very interesting, thanks @AbbeysDad and @Colin_T for sharing your knowledge and experiences.
Regarding "why 20ppm", I wonder if when around the time that nitrates were beginning to be understood as being dangerous to fish, the best the test kits could do was 20ppm. That would then have naturally created an entire generation of aquarists who were used to using 20ppm as a benchmark, and more accurate tests were treated as "yes there's nitrates but in my experience as log as you're under 20ppm which is all the old tests measured you are fine".
Perhaps there is a scientific basis for the 20ppm, again doing a medical analogy you don't draw your benchmark line at the level where 100% of people feel an effect, instead you usually take two standard deviations around the mean and say "ok 97% of people feel an effect at this concentration so we will use that number".
So ultimately to your point @Phreaker , you are right, 20 ppm is likely not the "magic number". Depending on each individual fish, it's age, it's life history, it's level of other stressors, it may be as low as 10ppm or lower, or a particular fish may be like "oh yeah I can definitely tell there's nitrates in here at 50ppm but I'm not gonna let that get to me, party on!".
Which is really the crux of this whole scientific methodology, isn't it? We like numbers because they simplify things, but when the numbers are (in the best case) determined off a bell curve, or (in a very typical case) determined off of "what worked pretty well before", you CAN'T say that 20ppm is exactly the number that is bad.
But maybe it's not the worst having the new fishkeeper coming to forums freaking out about 22ppm, because it's an opportunity to connect and it's an opportunity for conversation and sharing experience and collectively identifying best practices for all tanks - both those truly at risk and those where the owner is maybe just freaking out prematurely.
In the end, there are plenty of fishkeepers who have tested their water once or twice, decided that it was a waste of time, and have kept fish for years, with varying levels of success. They just don't generally show up on the forums.
Does it matter that the limit is 20ppm? Would it change anything if it was 10ppm? Taking a page out of public health, changing legal BAC values matters to a point, and after you get to the "magical threshold", changing the legal value will not have a meaningful impact on fatalities. It's probably a similar phenomenon here. Maybe 20ppm is a good rule of thumb, but people can fail or succeed on both sides of the value, depending on where their fish fall on the hypothetical bell curve.
Regarding "why 20ppm", I wonder if when around the time that nitrates were beginning to be understood as being dangerous to fish, the best the test kits could do was 20ppm. That would then have naturally created an entire generation of aquarists who were used to using 20ppm as a benchmark, and more accurate tests were treated as "yes there's nitrates but in my experience as log as you're under 20ppm which is all the old tests measured you are fine".
Perhaps there is a scientific basis for the 20ppm, again doing a medical analogy you don't draw your benchmark line at the level where 100% of people feel an effect, instead you usually take two standard deviations around the mean and say "ok 97% of people feel an effect at this concentration so we will use that number".
So ultimately to your point @Phreaker , you are right, 20 ppm is likely not the "magic number". Depending on each individual fish, it's age, it's life history, it's level of other stressors, it may be as low as 10ppm or lower, or a particular fish may be like "oh yeah I can definitely tell there's nitrates in here at 50ppm but I'm not gonna let that get to me, party on!".
Which is really the crux of this whole scientific methodology, isn't it? We like numbers because they simplify things, but when the numbers are (in the best case) determined off a bell curve, or (in a very typical case) determined off of "what worked pretty well before", you CAN'T say that 20ppm is exactly the number that is bad.
But maybe it's not the worst having the new fishkeeper coming to forums freaking out about 22ppm, because it's an opportunity to connect and it's an opportunity for conversation and sharing experience and collectively identifying best practices for all tanks - both those truly at risk and those where the owner is maybe just freaking out prematurely.
In the end, there are plenty of fishkeepers who have tested their water once or twice, decided that it was a waste of time, and have kept fish for years, with varying levels of success. They just don't generally show up on the forums.
Does it matter that the limit is 20ppm? Would it change anything if it was 10ppm? Taking a page out of public health, changing legal BAC values matters to a point, and after you get to the "magical threshold", changing the legal value will not have a meaningful impact on fatalities. It's probably a similar phenomenon here. Maybe 20ppm is a good rule of thumb, but people can fail or succeed on both sides of the value, depending on where their fish fall on the hypothetical bell curve.
kwi
Fish Herder
I also think the test kits testing on a logarithmic scale also has a lot to do with the 20ppm number. As mentioned I've read a few article stating 25ppm as a maximum for aquarium, but the test kits I have seen scale 5/10/20/40/60/160 so a 20ppm measure is easier than trying to decide is that shade of red 25ppm or 30ppm?
As anyone used these products for the help in lower nitrates. Reviews on amazon show these have helped others.
Seachem Denitrate 1 Liter
Algone; Controls nitrates, Ammonia, Cloudy Water & Algae
One of the problems I am having with my homemade aquasoil is that this stuff is an ammonia factory, which later becomes a nitrate factory. I do water changes every 3 to 4 days to help control nitrates. But my aquasoil grows plants like crazy especially rooted plants, but covering the substrate with plants still I have high nitrate production. I would have thought that plants would help nitrates, but they don't seem too.
While this is a new tank setup I have had fish in it since 7-16-2020 so over four months now and have not lost a single fish.
Seachem Denitrate 1 Liter
Algone; Controls nitrates, Ammonia, Cloudy Water & Algae
One of the problems I am having with my homemade aquasoil is that this stuff is an ammonia factory, which later becomes a nitrate factory. I do water changes every 3 to 4 days to help control nitrates. But my aquasoil grows plants like crazy especially rooted plants, but covering the substrate with plants still I have high nitrate production. I would have thought that plants would help nitrates, but they don't seem too.
While this is a new tank setup I have had fish in it since 7-16-2020 so over four months now and have not lost a single fish.
As an Amazon Associate we earn from qualifying purchases.
AbbeysDad
Fish Gatherer
Seachem Matrix and De*Nitrate are Pumice, a type of lava rock. It claims to have micro pores that will allow anoxic/anaerobic bacteria to process nitrates into harmless nitrogen gas. (think of live rock in SW). However, It can be very difficult in the high oxygenated FW aquarium (See My Nitrate Fight)
I believe that Algone is a resin like API Nitra-Zorb that comes in filter pouches that adsorbs nitrates. They work, and can be recharged and reused several times, but do have a use life as detritus coats surfaces and eventually limits the effectiveness.
Plants prefer ammonia over nitrates, but clearly your setup produces more ammonia than your plants can use so much gets converted to nitrates. I can't be sure what your homemade aquasoil is exactly, but it seems that although it may be great for plants, perhaps not the greatest for fish.?
I know 4 months seems like a long time, but fish want to survive. The real test is will they thrive for a year...two...five...ten???
It sounds like you might do 50-75% water changes twice a week - ? In time, your homemade aquasoil should settle down and behave better.
Footnote: I'm currently experimenting with Anoxic Biocenosis Clarification Baskets based on the research of Dr. Kevin Novak. Still, nothing beats routine partial water changes of sufficient volume and frequency to keep tank water FRESH-
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As an Amazon Associate we earn from qualifying purchases.
Thank you for the info.Seachem Matrix and De*Nitrate are Pumice, a type of lava rock. It claims to have micro pores that will allow anoxic/anaerobic bacteria to process nitrates into harmless nitrogen gas. (think of live rock in SW). However, It can be very difficult in the high oxygenated FW aquarium (See My Nitrate Fight)
I believe that Algone is a resin like API Nitra-Zorb that comes in filter pouches the adsorbs nitrates. They work, and can be recharged and reused several times, but do have a use life as detritus coats surfaces and eventually limits there effectiveness.
Plants prefer ammonia over nitrates, but clearly your setup produces more ammonia than your plants can use so much gets converted to nitrates. I can't be sure what your homemade aquasoil is exactly, but it seems that although it may be great for plants, perhaps not the greatest for fish.?
I know 4 months seems like a long time, but fish want to survive. The real test is will they thrive for a year...two...five...ten???
It sounds like you might do 50-75% water changes twice a week - ? In time, your homemade aquasoil should settle down and behave better.
Footnote: I'm currently experimenting with Anoxic Biocenosis Clarification Baskets based on the research of D. Kevin Novak. Still, nothing beats routine partial water changes of sufficient volume and frequency to keep tank water FRESH-
I was reading in your blog about aquarium substrates and in this you mentioned Father Fish. It was one of his videos on how he makes his aquasoil the inspired me to do the same. In this video he adds supplements that help the aquasoil to last for years before it needs replacing or recharging, if you watch some of his other videos he shows tanks he has had up and running for years.
AbbeysDad
Fish Gatherer
Well, okay, but I have 3-4" of inert pool filter sand in my 60g that I haven't touched in over 8 years - just add a root tab here and there for rooted plants
Ammonia, Nitrite and Nitrate test kits have been around since the 1970s and possibly earlier. They haven't changed since then and still use the same colour charts. The early Nitrate test kit colour charts went up to 100ppm and still do today.
Back in the day, people didn't worry about nitrates in freshwater aquariums and generally tested marine tanks. The maximum recommended nitrate level for marine tanks was 20ppm and that is probably where the 20ppm comes from. Corals and most crustaceans died when the nitrates got above 20ppm.
Personally I would like nitrates at 0ppm but that is never going to happen. So a happy medium is 20ppm, which most people should be able to achieve. It's low enough for fish to breed in and do their bit, and it takes a week or more to go up to 20ppm (assuming you start at 0ppm). This means you can do a water change every week or two and keep the levels quite low.
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Many years ago a company called Sera brought out a denitrator filter. It took about 2 months to cycle and housed anaerobic bacteria that converted nitrates into nitrogen gas and something else, both of which got released into the atmosphere after dripping back into the tank.
I ran one of these units on a marine tank that had lots of fish in and they were fed a lot of food. I did a 80-90% water change on the tank about once a month using natural sea water. That tank had 0ppm nitrate for the entire time the cycled denitrating filter was on it, which was several years.
The Sera Denitrator filter was a very simple design. It was simply an external filter that hung on the back of the tank. Aquarium water dripped into the filter and slowly passed through the filter media (course sponges) and dripped out the other end.
I fed the filter with a carbon tablet each day (as directed by the instruction booklet) and let it run continuously 24/7. After about 6 months of adding these carbon tablets I reduced them to one every few days and eventually dropped it to one a week. They didn't seem to make any difference. I think they might have been a sales gimmick because they cost about $25.00 a bottle and contained a one month supply of carbon tablets.
The flow rate in this denitrating filter was very slow. I had water dripping into it at 1 drop every 2-3 seconds. To get this flow of water I attached a T-piece and tap to some black irrigation pipe that was fitted to a power head. I ran some airline from the tap to the filter intake and let it drip in, one drop every few seconds.
You can easily make a denitrating filter using any external canister filter that is filled with really course sponge. Have a very slow flow rate and let it cycle (develop anaerobic bacteria). Then measure the nitrates coming out of the filter. It may need a source of carbon but it might not.
AbbeysDad
Fish Gatherer
My Nephew has a SW tank with live rock and a refugium and usually only does top offs. Never tested his water, but he says it works and his fish are awesome!
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John Strawn has the Aquaripure Denitrate Filter. It looks like a canister filter but uses an external pump to slowly move water through three layers of coarse, medium, and fine sponge material. The bacteria is fed vodka or grenadine syrup every few days. The return is about a drop per second. I guess it can work, but a little pricey.
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And then again, a LOT of plants, especially fast growing floating plants, just a few fish, fed modest amounts of high quality food, and water changes could be fewer and farther between.
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And agian, I'm experimenting [again] with Anoxic filtration.
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John Strawn has the Aquaripure Denitrate Filter. It looks like a canister filter but uses an external pump to slowly move water through three layers of coarse, medium, and fine sponge material. The bacteria is fed vodka or grenadine syrup every few days. The return is about a drop per second. I guess it can work, but a little pricey.
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And then again, a LOT of plants, especially fast growing floating plants, just a few fish, fed modest amounts of high quality food, and water changes could be fewer and farther between.
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And agian, I'm experimenting [again] with Anoxic filtration.
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