Acceptable Nitrate Levels.

[Fishiemang]

I have a 38 gallon bowfront heavily planted...even 'overstocked' by most standards I'm sure. Last water change was quite a while ago...when I moved into my house so...a little over 2 1/2 years ago. I add as it evaporates. That's it.

Another tank I have, moderately planted, a 30 gallon that is moderately stocked, last changed the water when I set it up 2 years ago. I add as it evaporates.

3rd tank, 10 gallon, heavily planted at this point, with a Jack Dempsy and a pleco in it for now, add as it evaporates...never change.

My 75 gallon, wasn't planted until very recently. Did water changes all the time. Lost most of the fish I had in this tank. Several varieties of african cichlids over the time it's been up. My severum and bala shark most recently.

When I ran into issues in the 75, I dug out my master kit. It's still sitting on the tank now, but I decided to test all my tanks...more or less to see how my theory is working out. My 75 gallon had good params, as expected for the amount of changes I did to it. My 38 gallon....perfect. 10 gallon.....perfect. 30 gallon....you guessed it...perfect.

Everyone has experience. I was a water changer up until a few years ago. I read an in depth article by a guy who was in his 80's and had been in the hobby since he was a kid. Don't remember where these days, but, yea. He said the line I use.

Be a water keeper.

Now...this doesn't mean you simply keep water, because that is impossible. Yes, plants use ammonia as food as well. Anywho...you maintain water quality. This is the point. As long as you maintain water quality, you will have healthy fish. Maintaining water quality is a multifaceted approach. You want to keep the micro and macro nutes in the column. You want to make sure the minerals and electrolytes are maintained in the column. You want to keep your BB up in the column.

Part of this guys ideas on this was you add back the nutes and electrolytes with new water. Whether changing it or adding when evaporated. The more important idea he subscribed to was the BB in the water column. Dude was a huge nature guy. He posed the question "How many filters do you see in a lake along the shore?". He also asked "How does nature take care of water changes?". He had other stuff in there too, about plant life, microbe life, everything from the air above, to the random bubbles that percolate up through the sediment. The snails. Slugs. Fish. Algae. He was telling people to think outside of the prescribed norms of this hobby essentially.

The answers were simple. No filters. Evaporation, and in some cases springs, for water changes. Plant life and.microbiome for nutrient and waste. Simple.

I find a lot of people tend to really overthink this hobby sometimes. It's not building rockets to go to the moon. Nature shows us every day how she takes care of it. Now, whether it's a massive lake, or a stream, or a small tank, the idea is the same. Be a water keeper, and life will thrive.

Now as to my findings from my habits, I have lost very few fish in the 3 tanks I have not done water changes in. Mostly they either grow old and get digested by snails when they fall to the bottom or go hide and die. Tanks thrive. I have lost the most fish in the tank I was doing water changes on to try and regulate the params. Something to be learned from here.

On a side note, I have not lost a single fish in my 75 since my severum and bala. I have also only done 1 small water change, just to bring the aquarium salt level back down. I didn't add much, far from the prescribed amount. But I also added some plants, scarfed from my other tanks. Added a few pest snails. This tank is thriving now. I am going to keep adding plants, and hold off on fish for a long while. I will be putting my Jack Dempsy in there when he is big enough, but, only plants. Soon, I will put this tank on the same regiment as my others.

Keep in mind as well. BB populations are in the water column, in the substrate, on the decorations and plants ect ect. Whatever you have in your tank. While there are some in the filter, I tear my filters apart every month and clean the spic-n-span and put them back with new cartridges (or just clean and put the media back in my fx4) and I never have a bacteria problem. I imagine it's because it has developed so well in the water columns that the filter is more for mechanical and flow mostly.

This is my story. It is hard to stray from habits. It is hard to step out on the fringe. But, when you look closely, you see the Earth has already perfected the process. All we need to do is follow her lead.

 

[eatyourpeas]

I think your tanks have achieved a nice balance and a key feature seems to be they are heavily planted. I hope to get to that point some day, but not there yet. I do find my heavily planted tanks are more forgiving when it comes to water change schedules.

My choice of critters seem to keep me always playing the balance game, and I continue to learn a lot. All my tanks have a sponge filter, not so much to keep the water quality but to provide a place for the ostracods to breed happily. Thanks to them my fish have food and I see very little algae.

If I ever have a large tank, I am learning about anoxic filtration. Very interesting method and quite like what is found in nature. @AbbeysDad has been a great resource, so thank you!

 

[AbbeysDad]

You want to keep your BB up in the column. The more important idea he subscribed to was the BB in the water column.

Beneficial bacteria is not in the water column, but firmly attached to hardscape, primarily the substrate in the established tank.

He posed the question "How many filters do you see in a lake along the shore?". He also asked "How does nature take care of water changes?".

Nature takes care of water changes with rains and snow melt. Where do you think the endless water supply comes from in all the creeks, streams, and rivers. And water is flowing through nearly all lakes with inlets and outlets. And springs are merely water coming up from below...that got there from rains! You've heard of Niagara Falls? The huge volume of water that flows in the Niagara river flows through ALL of the Great Lakes. The water flow of the Amazon river is so great on exit that fresh water can be collected 12 miles out at sea! Nature changes water...a LOT of water, day in and day out.

Now, whether it's a massive lake, or a stream, or a small tank, the idea is the same. Be a water keeper, and life will thrive. But, when you look closely, you see the Earth has already perfected the process. All we need to do is follow her lead.

Yes...and nature changes water all the time!
Old Tank Syndrome
So I think your 'old guy' was a bit confused about nature and keeping water. With rare exception, there's no such thing as too much fresh water. If you experienced issues with fish loss following water changes I'd question temperature, conditioner for chlorine/chloramine, or a dramatic change in water chemistry.

If I ever have a large tank, I am learning about anoxic filtration. Very interesting method and quite like what is found in nature. @AbbeysDad has been a great resource, so thank you!

Your welcome. My first attempt with BCB baskets failed due to soft clay litter that got mushy, however, I think the Safe T Sorb in my recent effort will be much better! (The principal is sound, like live rock and deep sand in salt water).

 

[thuctoanvietnamese]

Don't even test ammoniac and nitrate level LMAO.I just make small water changes everyday

 

[AbbeysDad]

Don't even test ammoniac and nitrate level LMAO.I just make small water changes everyday

You could do that - I know of some with auto water changes systems that do 25% daily. Then again, I've seen studies that conclude that doing larger volumes weekly or bi-weekly is more effective. (here it comes...)
"The solution to pollution is dilution!"
Don't get me wrong...having just a few fish that are fed sparingly with high quality food, in a heavily planted tank (especially with fast growing floating plants), with well established bio-filtration is GREAT.... But much like rain in nature, nothing will replace or eliminate the positive effect of routine partial water changes to replace polluted water with fresh water and replenish minerals.

 

[FishGuest5123]

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?
---
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.

Love this! I was thinking the same thing. Why be concerned with how much, just keep fresh water in your tank.

 

[DAnCSF]

What a great thread...just goes to show the variety of experiences we all have...alas what works for one doesn't necessarily it works for all. LIke any hobby, one has to distilled, organize, and try something to see what works for them. This particular thread is like quantum physics to many novices. For some there is nothing wrong with a hang on back filters and filter cartridges, yes I know some of you fish head sn fish nerds will howl at that suggestion. And yes there are nuances, exceptions etc....to HOB and filter cartridges....but why not start small and simple for novices so that they enjoy the hobby. There's plenty of time to spend the $$$, gain more experience and get really fancy. I lead a photography meetup group and my advice it novices is to put a new camera on auto and just enjoy taking pictures. There plenty of time to learn all the fancy buttons, techniques, etc... But the first step is just to enjoy the hobby.....cheers all...An initial deep dive into any hobby will usually just lead to frustration and abandonment, kinda like diving in the deep end of the pool without knowing how to swim...eh....

 

[AbbeysDad]

But the first step is just to enjoy the hobby.....cheers all...An initial deep dive into any hobby will usually just lead to frustration and abandonment, kinda like diving in the deep end of the pool without knowing how to swim...eh....

Too many aquariums end up in garages, basements, and on Craig's list because they were bought on impulse, not managed properly, the fish died, and the hobby was abandoned.
Some of us with decades of experience attempt to help enthusiastic new hobbyists that may be 'victims' of one or more of the many myths and poor advice out here. One reason that I created the Website/Blog. It's dangerous when someone suggests you don't need filter/tank maintenance and/or water changes. Dangerous for the hobby and potentially deadly for the fish. Sure, there are subtle differences, but the basics do not change.

 

[Fishiemang]

I have to disagree with some of your points.

Evaporation. Where does rain come from? The evaporation process. Water does not simply materialize as rain. The Earth has a finite supply of H2O. The evaporation cycle is what creates rainfall. Hence, water volume decreases via evaporation (which is essentially distillation), then builds up in the atmosphere as humidity, when it condenses it falls back as rain. With the rain, while distilled to begin with, picks up all the impurities in our environment. Then, as it falls back to Earth, the runoff picks up impurities in the dirt around the body of water. Some of this water percolates down through layers of Earth, getting filtered, and returns in some cases as spring water from deep under ground. Other times, the body of is below the water table, where springs flow out and into said body of water.

So in essence....evaporation.

The claim that beneficial bacteria is not in the water column is simply not true. Have you ever experienced a bacterial bloom? Does the physical items in the water turn white? Or is it that the water column itself clouds up? It's the water column. Yes, bacteria do attach to surfaces as well. The bulk of your BB is in your substrate in a well.established tank, not your filter. You also have it floating around in your water column. You have bacteria swimming around yourself in the air every single day of your life. It grows on your skin. You have more bacteria on your person, and inside your body, than you have cells that make up your body. To assume there is no bacteria in the actual water column is....silly at best. It is simply everywhere. It is on every thing. The trick is, much like our own micro biome inside our bodies, mainly digestive tract, is to maintain that balance of healthy, beneficial bacteria in the system. Any upset in this system leads to problems. The bacteria living on your skin acts to protect you from harmful pathogens. If you have an imbalance, or lacking fron excessive bathing (meaning more than once a day...at the most...some health practitioners prefer once a week) with commercial soaps, you will tend to be more sickly than another who practices more natural habits. That is the BB on your person will typically have given way to a opportunistic pathogenic bacteria, causing the ability to pathogens to enter the body. Same can be said for aquaria. Excessive cleanliness can lead to opportunistic pathogens to take hold and cause a litany of issues in the environment you have tried to create. So, the trick is to maintain the increased presence of beneficial "good" bacteria so that the pathogenic "bad" bacteria don't have the space, nor opportunity, to take hold and proliferate. It's a space game. You want the good guys to fill the joint up so there is no room for the bad guys to grow in numbers.

As.for old tank syndrome, I am not sure how people get to this point. I have not yet, and it has been years for my tanks. Years. Water is pristine and clear (see image). You see that layer in the substrate there that looks mucky? That's nothing more than algae growing on the glass because the fish cannot get to it to clean it. Otherwise, this tank has perfect parameters (when I checked a couple months ago after over 2 years of no water changes) and the fish thrive and are very active in this tank. My oto's are old. Ghost shrimp (a sort of.canary of aquaria) thrive and breed in this tank. Snails were thriving, until the food supply went down (they cleaned the hell outta the plant life in there), and now they can be found digging around the substrate. All signs point towards this 'old tank syndrome' being something more than simply not changing water. Again, nature does it's water changes in a very similar way to what I do. Water evaporates. I add it back. Simple. Never seen and type of 'old tank syndrome' in any of my tanks. I have dealt with fresh, marine and brackish. Like I said, I used to be a looney about water changes. I also used to spend a lot of money restocking fish (part of why I don't have a marine setup yet...those.guys get spendy)

We will have to agree to disagree on some points. I'm not telling you, nor anyone else, to go with what I do. I am not saying your way is any better or worse. I'm simply spelling out that there are many variables to this. With time, we learn to slow down (cause God knows time.speeds up on us as the years pass) and take stock of life around us. I spend a lot of time in nature. I am something of a naturalist, meaning I practice natural in most things I do, whether pets or myself. Plus, I read...a lot.

Another thing I am entertaining is moving a tank in.front of a bank of windows in my house. Getting rid of artificial lighting and letting nature handle that as well. This tank in the image enjoys sun every afternoon. The sun is essential for all life, and I am not sure that a little bit.of algae is worth not using it. As can be seen, stock the tank right and that's not an issue.

 

[HoldenOn]

I have a 38 gallon bowfront heavily planted...even 'overstocked' by most standards I'm sure. Last water change was quite a while ago...when I moved into my house so...a little over 2 1/2 years ago. I add as it evaporates. That's it.

Another tank I have, moderately planted, a 30 gallon that is moderately stocked, last changed the water when I set it up 2 years ago. I add as it evaporates.

3rd tank, 10 gallon, heavily planted at this point, with a Jack Dempsy and a pleco in it for now, add as it evaporates...never change.

My 75 gallon, wasn't planted until very recently. Did water changes all the time. Lost most of the fish I had in this tank. Several varieties of african cichlids over the time it's been up. My severum and bala shark most recently.

When I ran into issues in the 75, I dug out my master kit. It's still sitting on the tank now, but I decided to test all my tanks...more or less to see how my theory is working out. My 75 gallon had good params, as expected for the amount of changes I did to it. My 38 gallon....perfect. 10 gallon.....perfect. 30 gallon....you guessed it...perfect.

Everyone has experience. I was a water changer up until a few years ago. I read an in depth article by a guy who was in his 80's and had been in the hobby since he was a kid. Don't remember where these days, but, yea. He said the line I use.

Be a water keeper.

Now...this doesn't mean you simply keep water, because that is impossible. Yes, plants use ammonia as food as well. Anywho...you maintain water quality. This is the point. As long as you maintain water quality, you will have healthy fish. Maintaining water quality is a multifaceted approach. You want to keep the micro and macro nutes in the column. You want to make sure the minerals and electrolytes are maintained in the column. You want to keep your BB up in the column.

Part of this guys ideas on this was you add back the nutes and electrolytes with new water. Whether changing it or adding when evaporated. The more important idea he subscribed to was the BB in the water column. Dude was a huge nature guy. He posed the question "How many filters do you see in a lake along the shore?". He also asked "How does nature take care of water changes?". He had other stuff in there too, about plant life, microbe life, everything from the air above, to the random bubbles that percolate up through the sediment. The snails. Slugs. Fish. Algae. He was telling people to think outside of the prescribed norms of this hobby essentially.

The answers were simple. No filters. Evaporation, and in some cases springs, for water changes. Plant life and.microbiome for nutrient and waste. Simple.

I find a lot of people tend to really overthink this hobby sometimes. It's not building rockets to go to the moon. Nature shows us every day how she takes care of it. Now, whether it's a massive lake, or a stream, or a small tank, the idea is the same. Be a water keeper, and life will thrive.

Now as to my findings from my habits, I have lost very few fish in the 3 tanks I have not done water changes in. Mostly they either grow old and get digested by snails when they fall to the bottom or go hide and die. Tanks thrive. I have lost the most fish in the tank I was doing water changes on to try and regulate the params. Something to be learned from here.

On a side note, I have not lost a single fish in my 75 since my severum and bala. I have also only done 1 small water change, just to bring the aquarium salt level back down. I didn't add much, far from the prescribed amount. But I also added some plants, scarfed from my other tanks. Added a few pest snails. This tank is thriving now. I am going to keep adding plants, and hold off on fish for a long while. I will be putting my Jack Dempsy in there when he is big enough, but, only plants. Soon, I will put this tank on the same regiment as my others.

Keep in mind as well. BB populations are in the water column, in the substrate, on the decorations and plants ect ect. Whatever you have in your tank. While there are some in the filter, I tear my filters apart every month and clean the spic-n-span and put them back with new cartridges (or just clean and put the media back in my fx4) and I never have a bacteria problem. I imagine it's because it has developed so well in the water columns that the filter is more for mechanical and flow mostly.

This is my story. It is hard to stray from habits. It is hard to step out on the fringe. But, when you look closely, you see the Earth has already perfected the process. All we need to do is follow her lead.

Did you say a Dempsy in a 10 G? It's but a fry right?

 

[Fishiemang]

it's about 3 inches right now. I put him in there when he was about an inch. Got beat up pretty bad in my 75 gallon, and I found him just in time. Fins were gone. Was tucked up in some water wisteria that I had in there at the time. I nursed him back in a hospital tank, then set the 10 gallon up for him to live in until he gets big enough to play with the big boys in the big boy tank. Then the 10 gallon will be a shrimp tank.

Just took this just now...

 

[AbbeysDad]

The Earth has a finite supply of H2O. The evaporation cycle is what creates rainfall. Hence, water volume decreases via evaporation (which is essentially distillation), then builds up in the atmosphere as humidity, when it condenses it falls back as rain.

The earth is 75% water. Yes water (largely ocean water) evaporates, condenses, and falls back to earth as pure, fresh rain water. It's filtered through the soil where it picks up minerals. Much of this fresh water flows back to the oceans and the process repeats as it has for eons.
But this is not the same as topping off your tanks to compensate for evaporation as unlike natural fresh water, you are not replacing polluted water.

The claim that beneficial bacteria is not in the water column is simply not true. Have you ever experienced a bacterial bloom?

Yes there are many different types of bacteria and conditionally there are some that are water borne like the blooms you referenced. But when we speak of beneficial bacteria in the aquarium, we're speaking of nitrosomonas and nitrospira that process ammonia and nitrites into nitrates and these bacterias do not live in the water column, but attach to solid surfaces.

As.for old tank syndrome, I am not sure how people get to this point.

As pointed out in the article, old tank syndrome happens slowly over time as pollution slowly builds resulting from neglect. Not much different than animal cages or horse stalls if they're never mucked out. In the absence of tank/filter maintenance and partial water changes, water quality degrades. pH lowers as water becomes acidic. Ammonia gets converted to ammonium so it's not toxic to fish so the fish may 'look' fine.
Although we tend to use nitrates as our measure of pollution, there are other pollutants as well that plants alone will not remove. I didn't invent old tank syndrome. We've known about it for many decades and volumes have been written about it. Here's a good article to explain.
I can't possibly explain how you're getting away with not doing partial water changes. I will say that you do not have the test equipment to analyze and compare the chemistry of your tank water to fresh water. I would bet that your tank pH is lower than your tap water and your tank kH/gH is likely quite different as well. Phosphates are also likely high.
---
The real concern I have is that when someone like you 'brags' about not doing water changes, another myth gets created when new hobbyists buy into the claims and stop doing partial water changes. Most will not be successful and a few more tanks may go to garages, basements, or Craig's list.

 

[mcordelia]

I also want to add to this that it's important to not confound levels of scale. The scale of what occurs in a fish tank is largely different than the scale of the planet, and confounding the two is just, bad science if nothing else.

For instance, while on the surface the idea of evaporation and water replacement are the same processes in both your small fish tank and a large lake, the economies of scale (and location) are vastly different. As water evaporates from the lake, it condenses into clouds. Clouds are then pushed by the wind to a different area, and when sufficient meteorological or geographic changes are encountered by the clouds, the water condenses further, becomes heavier than the surrounding air, and falls back to the ground. Note, that water does not fall into the same lake that it came from.
Then, there is likely a stream or a river that is feeding said lake. That river is supplied by snow melt, rainfall, other lakes, etc, which result in any particular mineral and oxygen concentrations for that specific body of water, which help establish the water parameters of the lake.
Finally, the lake itself is likely to feed other streams or rivers, providing yet another outlet for the water. Potentially massive amounts of toxins that the fish produce are flushed out of the lake itself. If that specific river then has a waterfall or rapids, it gets rapidly oxygenated, resulting in factors of scale of beneficial bacteria being able to process the toxins in the water that man can only dream of emulating in their fish tanks.

So while yes, it all does come down to evaporation, that's kind of like saying that the air quality inside of your house is as good as the air quality in a forest of a sparsely populated country just because you run a HEPA filter.

The next item I wanted to address is the concept of beneficial bacteria. Yes, you are correct in saying that every surface of our bodies, as well as every surface and the water column in your fish tanks contain bacteria. However, not all bacteria are created equal. Bacteria that live in your colon are not adapted to surviving long term on your skin (for the most part, there are some exceptions which can make you exceptionally sick), and zooming into the digestive tract even further, the bacteria that live on your teeth are vastly different than the bacteria that live in your stomach, even though obviously every day thousands of the bacteria on your teeth travel on your food into your stomach. But they can't survive there. Similarly, of course the "beneficial bacteria" can be found in small quantities in your tank water. but to say they're anything but a negligible component is committing the same fallacy as claiming that the bacteria from your teeth would be forming colonies in your stomach just because they have a way of getting from A to B.

I think this touches on the larger social topic of science literacy. I am very disappointed in the United States public schooling institution, since science literacy in graduates of most school systems in this country is very poor. It is a disservice to the population that we are not taught to be better critical thinkers, and taught how to better evaluate scientific concepts. It's really not rocket science to understand the concept of bacteria, or rudimentary chemical principles, or heck, even rudimentary aspects of formal logic. I routinely see these kinds of fallacies and jumps in advertising, and it makes me angry that people are shelling out money for products that are not scientifically sound, simply because they have not been given the basic tools in their education to be able to intelligently evaluate the baseless "Scientific claims".

ok I am going way off on a tangent here and this is starting to sound way too much like a political argument, and nobody wants that. But bottom line: it is imperative that all of us understand economies of scale, and not mixing the micro and the macro is vitally important, both in aquaria as well as in economics

 

[seangee]

I also want to add to this that it's important to not confound levels of scale. The scale of what occurs in a fish tank is largely different than the scale of the planet, and confounding the two is just, bad science if nothing else.

For instance, while on the surface the idea of evaporation and water replacement are the same processes in both your small fish tank and a large lake, the economies of scale (and location) are vastly different. As water evaporates from the lake, it condenses into clouds. Clouds are then pushed by the wind to a different area, and when sufficient meteorological or geographic changes are encountered by the clouds, the water condenses further, becomes heavier than the surrounding air, and falls back to the ground. Note, that water does not fall into the same lake that it came from.
Then, there is likely a stream or a river that is feeding said lake. That river is supplied by snow melt, rainfall, other lakes, etc, which result in any particular mineral and oxygen concentrations for that specific body of water, which help establish the water parameters of the lake.
Finally, the lake itself is likely to feed other streams or rivers, providing yet another outlet for the water. Potentially massive amounts of toxins that the fish produce are flushed out of the lake itself. If that specific river then has a waterfall or rapids, it gets rapidly oxygenated, resulting in factors of scale of beneficial bacteria being able to process the toxins in the water that man can only dream of emulating in their fish tanks.

So while yes, it all does come down to evaporation, that's kind of like saying that the air quality inside of your house is as good as the air quality in a forest of a sparsely populated country just because you run a HEPA filter.

The next item I wanted to address is the concept of beneficial bacteria. Yes, you are correct in saying that every surface of our bodies, as well as every surface and the water column in your fish tanks contain bacteria. However, not all bacteria are created equal. Bacteria that live in your colon are not adapted to surviving long term on your skin (for the most part, there are some exceptions which can make you exceptionally sick), and zooming into the digestive tract even further, the bacteria that live on your teeth are vastly different than the bacteria that live in your stomach, even though obviously every day thousands of the bacteria on your teeth travel on your food into your stomach. But they can't survive there. Similarly, of course the "beneficial bacteria" can be found in small quantities in your tank water. but to say they're anything but a negligible component is committing the same fallacy as claiming that the bacteria from your teeth would be forming colonies in your stomach just because they have a way of getting from A to B.

I think this touches on the larger social topic of science literacy. I am very disappointed in the United States public schooling institution, since science literacy in graduates of most school systems in this country is very poor. It is a disservice to the population that we are not taught to be better critical thinkers, and taught how to better evaluate scientific concepts. It's really not rocket science to understand the concept of bacteria, or rudimentary chemical principles, or heck, even rudimentary aspects of formal logic. I routinely see these kinds of fallacies and jumps in advertising, and it makes me angry that people are shelling out money for products that are not scientifically sound, simply because they have not been given the basic tools in their education to be able to intelligently evaluate the baseless "Scientific claims".

ok I am going way off on a tangent here and this is starting to sound way too much like a political argument, and nobody wants that. But bottom line: it is imperative that all of us understand economies of scale, and not mixing the micro and the macro is vitally important, both in aquaria as well as in economics

Also worth recognising that water evaporates, but minerals, hormones, pheromones (etc etc) do not.
So if there are any minerals in your tap water (which is highly likely) the concentration increases over time. One characteristic of old tank syndrome is that the fish appear fine because they have gradually been exposed to these increased concentrations so are able to tolerate it. Adding new fish often results in rapid death of the new fish - because the water is so different to what they expect.

 

[Fishiemang]

We are overthinking again.

75% water? Maybe the surface. Haha. 5th grade science will demonstrate this.

Confounding by comparing habits of maint to nature? Bad science? Since when is building a small ecosystem based off of large scale bad science?

Look.

The idea I cover here is simply just water keeping. It only covers maybe...20% of the idea. I'd be typing, and quoting various links, for days to cover it all. This practice involves copying what happens in nature. Not just water. People who operate on the sole idea that "the solution to pollution is dilution" are not paying attention to their other habits causing pollution. If you need to resort to this method of water keeping, then you're missing an opportunity. What causes pollution? More than simply fish waste. In a well built eco system, fish waste is dealt with readily and effectively. The ammonia never reaches a level that is converts to ammonium. Levels of all items monitored never exceed acceptable.

We are overthinking.....and overlooking.

In nature, how often do fish have a steady supply of people dropping food into the water for them? Never. They have to scavenge for their daily meal. This is natural. They get the opportunity to hop out of the water for flying critters, or the ones that fall off a.stray tree branch. So the idea to feed multiple times a day in small amounts is a thing maybe to do at first, but in a well established tank, you can cut this back dramatically, and allow the fish to scavenge for their food. This is nature. Then you add things that take care of leftovers that drift down to the substrate. This eliminates the possibility of leftovers rotting in a tank. Whatever waste produced is reduced. Whatever is left gets broken down, converted, and used by the other life in the system.

As for water degrading, you'd need to allow it to become stagnant first. Flowing water is life water. Stagnant water is dead water. We can dive into the chemistry of it all, but that would again involve days of typing and quoting. You have a filter, or some form of water agitation? This oxygenates the water. Flowing, oxygenated water does not become acidic, unless you again have somewhere else in your process causing the acidity to form. Water is neutral. It is only as good as what you do with it. It is 3 molecules. Flowing water will always be life giving water. From the largest oceans to the smallest mountain springs.

I can go on for days. My point to all of this is I am presenting proof that what I speak of is possible, and effective. I am not speculating here. I have done it. I still do it. My tanks thrive. The water is pristine, and life giving. The various species in these tanks proliferate. It is not the dark, neglectful thing you are thinking it is.

Don't overthink. Just look at what nature does, and do your best to copy that. For whatever species of fish you keep, that is the ecosystem to build. Not just water, but also the rest of the life in that system that makes it possible for that system to sustain life, without human intervention.