Are Water Changes Actually Necessary?

[Bushtech]

I do a 1/3 water change every 2 weeks even though my water tests never seem to change - 0 ammonia, 0 nitrites, less then 5% nitrates. I know the other perameters are rising. I do not need to test for them, it's a given.
One cannot simply and continually add tap water to replace evapourated water without increasing the disolved kh and gh in a set volume of water. These elements along with others from the tap water do not evapourate or go away on their own. They accumulate with every drop of water added to the tank. Only a water change program can keep their levels in check.
I have limestone, natural river run gravel and drift wood in my tank which with time, disolves and break down adding to the disolved solids.
Fry whether Angel fish or Guppies will be deformed if water changes are not part of the program. This is an observation and a fact.
An "old tank" condition is an ideal growing enviroment for hatchlings. However when I say "old tank", I mean clean water (regular water changes) with out removing the nutrient rich algea from drift wood and the 2 sides and back glass surfaces).
Deep sand/gravel bed or muck bottom in an aquarium are not representitive to what occurs in a sand/gravel bed or muck bottom in a natural setting. In a natural setting water would perculate through these mediums and not sit stagnant as in an aquarium.
One other point. If you run into a situation where you have to do a large water change (due to a move, changing to a larger tank, an emergency, etc) where are you going to get the replacement water with your perameters? My tank water perameters, like all those who do regular water changes, are never far from the source (our local tapwater).

 

[sorberj]

Also, keep in mind that in a "natural" setting, particularly in a river, there is an annual flood/dry cycle that alternatively lifts and rinses the substrate of organics, and dries it to kill off pathogens. It's never 100% clean, but if you've ever seen a river in flood stage, you'll know that there's a whole lot of rinsing going on.

 

[tekonus]

K, I've just run across this thread and browsed every page for at least the brief gist of the convo on it. I believe quite a few people have made valid points in the last 5 or more pages and the only post responded to by the OP was

Your old pipes might be terrible, or they might be wonderful. That's only the roughest of data for a starting point.

You definitely are better-off knowing the condition of your water. Even if you're not going to maintain fancy testing kids for years, you might want to get the water tested at the outset, so you know what you're dealing with.

Hopefully, if you're not talking about a marine tank, you can use the tap water, you just will need to know what, if anything, needs to be done to make it safe. Even dechlorinator can, for example, get rid of some heavy metals.

I don't drink tap water. The local government's proud announcement about how much lower the lead is than last year (when they didn't say anything at all) is a great example of why.

Don't even get me started on how state-mandated monopolies, like water departments, are bad for society.

So... I'm pretty sure the point has been made. The truth is... the earth and all its glory is something that even in this day and age we don't completely understand yet. Yes we know lots, and we may THINK we know everything... but new discoveries are made all the time. So how about you make a compelling argument for how you can take the scope of something human-kind can't even fully understand the workings of and replicate it in a small glass box?

I'm also quite curious what your qualifications are that make all the facts you've used definite.

 

[kazvorpal]

Not sure if my thoughts have been covered but:

1. In aquariums with fish that come from higher pH (african cichlids and such), the pH will lower as old tank syndrome occurs. Plus, with plants, they can't help with nitrates due to the fact that african cichlids eat them up (unless your talking about Anubias or Java Fern.) But those plantss are slow growers and aren't gonna suck up much of the nitrates. Also, I think lower pH has effect on snail shells (which you'll probably need to clean algae) which could cause shell erosion and such.

Then this would imply that one should test the pH and nitrates, and change water IF they become a problem.

Of course you could still use a deep sand bed, mud filter, ceramic foam, et cetera, to keep the nitrates near zero without water changes.

2. In a planted aquarium, people use macro and micro ferts, and a build up of those would be too much. When you dose, you kinda dose for the amount of water you took out. Also, you seem to be considering things in terms of planted tanks. Not everyone keep planted tanks. People keep african cichlids, some people with fake plants, and salt water.

This implies that everyone both uses fertilizer, and uses too much.

You should only use it if you need it, and only to the extent that appears necessary.

In fact, many people don't fertilize. They don't need to.

3. What about fish that get sick? You're just gonna let mother nature take it's course and let all the other fish get sick from it? You're gonna have to change the water to dilute the amount of "bacteria/viruses" and possibly eliminate the disease.

While you aren't actually going to be able to eliminate most diseases by a water change, this is actually a good reason.

Yet it has nothing to do with the claim that we should change our tanks on a specific routine, without specific cause. That is what I'm questioning.

4. What about the build of up sediments? In a society where money is tight, not everyone is going to be able to buy that "Holy Filter" that just sucks up all the sediments. You don't want your poor old cories swimming in poop, do you?

Again, this is a reason to specifically vacuum your tank, if you have a freshwater tank with gravel, and don't like the mess. I don't really care if the cory swims in poop, though, because he doesn't care, because that's what he does in the wild. People seem to get the delusion that all fish evolved to be in nice, pristine water conditions. In fact, bottom-feeders are specifically evolved to be in messy, dirty, muddy water. It may even be better for them. But we humans care more about the tank being pretty for our sake, than our fish being in the conditions they would find optimal...as someone on here was honest enough to say of himself.

5. When you talk about adding salt, have you considered fish such as Loaches and Corydoras? Neither can take salt because they are scaleless. Loaches just have skin and Corydoras are a little better with their armoured plating. It's always recommended not to add salt when keeping them.

Bwahahaha! Mostly, I try to treat what people say seriously, but that's just too goofy.

Many catfish live, in the wild, in brackish water, even salt water. Many other scale-less fish live in brackish water, even marine salt water. What, do you think that life evolved in fresh water, and then had to evolve scales to protect it from salt water? Do they have scales inside, too? Life evolved in salt water. Whether a fish has scales has ZERO to do with whether they are adapted for salt.

In fact, only SOME corys (and no loaches that I know of) are sensitive to moderate salinity, and only because they evolved in abnormally low-salt conditions. MOST "fresh" water is at least somewhat brackish.

Silver tipped sharks (a kind of Columbian catfish) not only prefer brackish water, despite their scale-free condition, but thrive in full marine salinity.

There are a few salt-sensitive "freshwater" fish, but most others are best off in brackish water. I keep my cichlid tank at 1.005, fully brackish. They are, therefore, largely protected from any freshwater parasites. Since I started using brackish in my freshwater tanks over a decade ago, I have never gotten (for example) freshwater ich, and yet don't bother to quarantine new additions. Ich simply can't live in brackish water, and the fish can.

In nature, (since we keep referring back to it), water is constantly doing "water changes". Rivers, lakes and streams (not sure of the ocean). Unless you want to flood your tank or hook it up to a river, you're going to have to sometimes do water changes.

Absolutely: Sometimes. Under specific conditions. So far, there's no real case being made for every day, or every week, or such condition-unrelated routines. I think some people are just creatures of habit, and others are just blindly following what they were told.

 

[kazvorpal]

You may not think your fish are unhealthy, but it is inhumane to make a fish live in its own waste. I like the analogy of leaving someone in a port-a-potty for a long period of time. Ammonia and other things build up, and these are toxic. Your fish may have been very hardy species, and you must have gotten lucky. Not only can fish be sensitive to the toxins, no wc's stunts growth.

No, ammonia does not build up. In fact, most tanks will NEVER see an accumulation of ammonia, once the normal biological cycle has been established.

It is "inhumane" to leave fish swimming in what you imagine to be their own waste, only insofar as you are errantly anthropomorphizing the fish. Many of them live, more or less specifically, in almost nothing but waste, in the wild. That is largely what the muck at the bottom of a pond or river is comprised of.

I can't believe that people would consider not doing wc's. Even when I was 5 years old with a betta in a little plastic box, I knew to do wc's. And no one told me that, it just made sense.

That is hardly an argument for it. Some children think it makes sense to eat only candy, or to pee in the cat box. A betta is a prime example of a fish that should NOT have dramatic, or frequent, water changes. In the wild, it lives in stagnant swamps and mud puddles.

 

[kazvorpal]

Here's just one paper on PubMed. I'm tired and want to go to bed. Unfortunately, there's not a lot of research on the actual aquariums out there, but there are a few things that we can say.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2644126/?tool=pmcentrez&report=abstract

Oh c'mon, that article centers around the NIH trying to find a way to exploit the global warming myth. It involves them artificially imposing increased CARBON DIOXIDE levels in water, to acidify it a-la Coke dissolving meat.

Ocean acidification impairs olfactory discrimination and homing ability of a marine fish

1) Lower pH is bad for marine fish
2) Urea is acidic
3) build up of urea causes lower pH

Urea is part of the nitrogen cycle. That is why it's used as a nitrogen release in fertilizer. It doesn't "build up" in a tank with a healthy cycle going on.

4) addition of buffers will correct lower pH - UP TO A POINT
5) once you've added a certain amount of buffer, the negative components of the buffer mixture will lower pH despite the addition of additional buffer.

Having aragonite or calcite, or crushed coral, in your tank imposes a permanent buffer. They react chemically with acidity.

This is basic chemistry. There is nothing that can increase the pH of marine water once certain chemical pathways are saturated.

Which is simply not going to happen in a saltwater tank, from urea. Especially if you have live rock and calcium-based media.

A partial water change will reset (at least partially) the chemical pathway for the maintenance of pH (indeed, it does the same for other chemical pathways as well, ammonia, nitrites, nitrites, phosphorus, etc). A regular water change will prevent the chemical pathways from ever 'clogging up' and needing emergency maintenance.

This is only an argument for watching the pH and nitrates, and doing a change if you are unable to keep them stable in some other way.

It is most clearly not an argument for routine changes.

Again, it needs to be said that freshwater fish can often survive quite happily in water that is not ideal. Again, it's survival. Roughly akin to the guy who hasn't cleaned his apartment in 2 years. You can live in it, but who wants to.

On the other hand, that guy who hasn't cleaned his apartment for two years probably is not stressed or made unhealthy by it. Most of us prefer our homes cleaner, but it's not REALLY for health reasons. Some sound science has made a case for over-clean homes as a fundamental cause of the mysterious increase in asthma in recent years.

Now, as far as anecdotal evidence goes... I had two tanks: a 55g freshwater tank planted with cories, black skirt tetras and neons, and a 46g reef tank with much natural life (in fact the entire tanks was basicaly 75 pounds of Gulf of Mexico reef removed and dropped into my tank (arguably as close to natural as you can get)).

Hurricane Ike comes in and we lose power for 6 weeks. The SW tank was the third most disgusting thing I've ever dealt with in my entire life. The freshwater tank had some algae growth... didn't even lose a fish. As far as I know, every fish I had is still alive.

What was this evidence of? That an unheated tank with no water circulation won't kill your fish? Since it was gulf coral and inverts, that doesn't surprise me, although some other species absolutely need strong current to thrive.

But what had that to do with water changes? Did you not change your water normally, without electricity? Because you lived in a hotel for the 6 weeks?

 

[Turbosaurus]

You're got to be kidding me kazvorpal. :help:


Most fish are brackish? Corys like salt? Catfish live in muddy water? What are you smokin? (and can I have some?)

 

[tekonus]

Blah... I'm sorry I said anything, he was quiet for a while...

 

[chefjamesscott]

I do water changes because of the need to remove TDS which i do not have a way to measure. This is just from a quick wiki search:

Total Dissolved solids

High TDS levels generally indicate hard water, which can cause scale buildup in pipes, valves, and filters, reducing performance and adding to system maintenance costs. These effects can be seen in aquariums, spas, swimming pools, and reverse osmosis water treatment systems. Typically, in these applications, total dissolved solids are tested frequently, and filtration membranes are checked in order to prevent adverse effects.
In the case of hydroponics and aquaculture, TDS is often monitored in order to create a water quality environment favorable for organism productivity. For freshwater oysters, trouts, and other high value seafood, highest productivity and economic returns are achieved by mimicking the TDS and pH levels of each species' native environment. For hydroponic uses, total dissolved solids is considered one of the best indices of nutrient availability for the aquatic plants being grown.
Because the threshold of acceptable aesthetic criteria for human drinking water is 100 mg/l, there is no general concern for odor, taste, and color at a level much lower than is required for harm. A number of studies have been conducted and indicate various species' reactions range from intolerance to outright toxicity due to elevated TDS. The numerical results must be interpreted cautiously, as true toxicity outcomes will relate to specific chemical constituents. Nevertheless, some numerical information is a useful guide to the nature of risks in exposing aquatic organisms or terrestrial animals to high TDS levels. Most aquatic ecosystems involving mixed fish fauna can tolerate TDS levels of 1000 mg/l.[4]


Daphnia magna with eggs


The Flathead minnow (Pimephales promelas), for example, realizes an LD50 concentration of 5600 ppm based upon a 96 hour exposure. LD50 is the concentration required to produce a lethal effect on 50 percent of the exposed population. Daphnia magna, a good example of a primary member of the food chain, is a small planktonic crustacean, about five millimeters in length, having an LD50 of about 10,000 ppm TDS for a 96 hour exposure.[5]
Spawning fishes and juveniles appear to be more sensitive to high TDS levels. For example, it was found that concentrations of 350 mg/l TDS reduced spawning of Striped bass (Morone saxatilis) in the San Francisco Bay-Delta region, and that concentrations below 200 mg/l promoted even healthier spawning conditions.[6] In the Truckee River, the Environmental Protection Agency (EPA) found that juvenile Lahontan cutthroat trout were subject to higher mortality when exposed to thermal pollution stress combined with high total dissolved solids concentrations

just thought I would quote this one

I got too busy to change a community fish tank once, for about a year and a half. I also only fed them (reliably) about twice per week. Go ahead and try this with some larger carnivourous fish and see what happens.

In that period, I did not lose a single fish.

Deciding I may be "on to" something, I continued that treatment even when I had plenty of time. In the next two years, I lost one molly, whom I'd had for perhaps five years and seemed simply to be getting old and feeble.

So your claim that if you don't change the water, fish die, is only anecdotal. Perhaps that happened to you...but you don't know for certain that lack of water changes is what caused it...while I can say for certain that lack of water changes did NOT kill my fish, because they did not die.

I can absolutely assure you that if you are into keeping larger fish than those you have mentioned that not changing your water will indeed bring about death. Perhaps your smaller planted tanks with tiny tiny fish can handle what you propose, but try that with a 200+g tank with large cichlids or other fish and see what happens.

Also, I was not the one who suggested electrolytes as a reason for water changes, I was saying that someone else claimed this...while claiming to be a scientist in a related field.

As for "removing waste", that is what the tank's own ecosystem will do, without any intercession on your part, if you set up the tank properly.

Sorry totally do not agree with this. In a nature setting there are way to many variables that can not be reproduced in a aquarium. Take for example the types of fish that I keep GOOD LUCK trying to keep them planted! So there goes the tank's own ecosystem you so propose is easy to set up. Tried that and watched my fish absolutely destroy $100's in very nice plants.

Most people, almost incidentally, end up with a tank capable of converting ammonia into nitrates and nitrites, and nitrites into nitrates.

That's where casually set up tanks usually fail. Nitrates generally need either plants or anoxic organisms to break them down. But we now know that there are many ways you can set up a tank to host those things.

And no, the water does not gain or lose elements. Spontaneous generation only happens on a quantum level, if at all. Again, this is too vague.

As a chef I will not get into a huge detailed chemistry lesson on how water does indeed gain or lose elements with you. Suffice it to say with fish that are 9-25 inches in length they do indeed contribute some elements to the water that must be removed with water changes. Simple because their natural range is much much much larger than the 6-10 ft tanks they live in and therefore the waste they produce is much more than the ecosystem of their glass box can deal with on its own.

If there are specific elements, find out what they are, and let us know. Also, let's figure out how to measure them, and how to add/remove them.

You certainly don't ADD many elements by changing water, except the minerals that make water hard.

Friend you rock on with your belief that it is not necessary to change water if you wish but I totally disagree with you.

And I will not put things like my $3000 colony of wild caught, F1 and F2 frontosa at risk. Nor will I put my other colony of 6 fronts, with my colony of 11 river botia(which by the way are used to fresh flowing river water), with my 23 inch silver arowana. etc... etc... etc....

"Carry on my wayward son, there will be peace when you return home...."-Kansas

 

[Trigger1985]

If not changing your water works for you, then fine. I however will continue to change my water weekly for a multitude of reasons.
TDS- I'm keeping fish on a shoe string budget, I just traded my brother a spare tank to get the ferts I want to use to raise my plants- so for now I can't afford any extras like TDS meters- so to make sure it's in safe range, I continue with my weekly water changes.
EI dosing- I use EI dosing- a method that requires weekly water changes to dilute any remaining extra ferts to avoid oding the tank- once again can't afford the extra meters or kits to know the exact ppm of every chemical needed for plant growth.
Tannins- I have large pieces of driftwood, that despite weeks of soaking is still leeching tannins, which soften water and lower ph, not to mention turning the water so dark I can't see the back of the tank if I slack on water changes.

Other pollutants- there are any number of chemicals in the air at any given time, from air pollution, to household chemicals to the smoke from the neighbors fire pit. Any of these will end up in the water, my fishtank isn't a sealed and airtight system, so who knows what ends up in there. The solution to pollution is dilution, so I'll keep changing the water to keep god knows what from accumulating.

The one reason I don't have to change my water is Nitrates- I've never seen them get over 5 ppm without ferts in my tanks. My plants and if your correct, anaerobic zones in the deep sand substrate are to thank for my low nitrate levels.

Personally I probably won't cease my water changes at any point, if you've found a way to keep a tank going without it, then awesome, but the same some people will always use undergravel filters, because it's always worked for them, I'll stand by my water changes.