Do you consider a water change to be an effective type of aquarium filtration method?

BRS

Do you consider a "water change" to be an effective type of aquarium filtration method?

  • Yes

    Votes: 358 67.5%
  • No

    Votes: 113 21.3%
  • Not sure

    Votes: 39 7.4%
  • Other (please explain)

    Votes: 20 3.8%

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WhiskyTango

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I think the question is awkwardly worded. If you actually look up the definition of the word 'filter'. It is passing liquid/etc through a device to remove something. In that sense - adding bacteria is not a filter. IMHO - the question is asking 'Can water changes act as a filter by removing undesirable chemicals from the water'. The answer to that question again only my opinion is yes.
That's because its a silly click baity question designed to generate participation and clicks. A water change is not a filter.
 

MnFish1

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Please help me to understand. (I did read the article you posted, I love reading your stuff. I did have to google things to understand what they were.)

If the organisms we keep are intentionally secreting organics, and they will continue to do so, then how is the math on that organic removal not similar to using water changes to remove nitrate.

If anything wouldn't the organisms secrete greater amounts of organics as they grew larger?

When we do a water change of say 20% we would only remove 20 % of the secreted organics. The organisms would continue to produce more. The next water change would only remove 20% of the now higher number. So on and so forth. Eventually the secreted organics would rise to a level of toxicity. It might take longer then it would with the more commonly understood elements but wouldn't they eventually arrive at the same conclusion?

Also to clarify my stance on water changes as it seems to be misunderstood. I am not against them, but would not label a filter which needs several other filters, as effective. To many hobbyists read that all they have to do is change 10% of the water every week and their tank will be successful. I haven't found this to be the case. There is simply more to it.


Also, in personal experience I have kept systems for as long as 4 years in between water changes, only adding new water when water was removed fragging corals. My tank was full of corals, Monti's bigger then a basket ball, pagoda cup I could use as a lid to a bucket, all grown from the size of a quarter. IME I never ran in to a toxicity issue with DOMs (or POMs). Do you have any hypothesis on why certain systems can thrive without water changes for so long?

Thanks for taking the time to explain this to us.
Your premise seems partially incorrect to me. To answer the question, you would need to know how quickly the 'undesirable chemical' is being produced.

For example - let's say you have a coral - that was producing xxx and the only coral producing xxx is removed (such that no more xxx is produced). 20% water changes will eventually remove more and more with each change until the amount tends to 0.

On the other hand, Lets pretend that The coral produces. 1 mg of xxx every week, and you do a water change 20% - and that removes 1mg of xxx. IN that case the amount of xxx in the tank will basically drop by 20 percent - and then increase back to the original amount (only to be removed again with the next water change)

Take the above example and assume that a 20 percent water change removes 2 mg of xxx. In this case, over time the level of xxx will again approach zero - but more slowly.

Likewise, if a 20 percent water change only removes 0.5 mg per change, the level of xxx will slowly increase (This is the only way the level will increase over time - all of the other examples will result in the same or less xxx in the tank
 

MnFish1

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It depends on what you are doing and what you hope to accomplish.

Math tells us:

1. You can not keep a tank at proper levels long term with water changes where the new water is at sea levels.

2. You can also not remove pollution long term using water changes.


They are effective for some things, and as part of a filter strategy, in some cases but not others. Tank size also matters. Doing a 50% change on a 10g tank with nitrates at 100 is probably the easiest option. For a 1000g tank, there are better options. That is why we see such huge contrasts in peoples experiences.

When I was breeding fish, a 50-100% daily water change was sometimes necessary. If there is a problem in a tank that needs correction a large water change is great. A weekly 10% change may help people who are not keeping levels appropriately if there livestock is low need and they use replacement water at elevated sea levels.

So a complete answer to the question, like many things in this hobby is it really depends on the situation.
I'm going to disagree with point 2. Take this example. Let's say you do 100 percent water changes every day. You will remove all pollution short and long term. It all depends on the rate of production of whatever pollutant is in the specific tank. If you're not removing 'chemical xxx' faster than chemical xxx is being produced you're correct it will slowly increase.

Sorry - I'm also going to disagree with point 1. Math does not tell us what you're saying.
 

MnFish1

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I look at it like this, with those that dose we are spending money to dose the tank maintain certain levels only to change those levels with water changes,

trace elements can be dosed back to the tank, nitrate and phosphate can be removed other ways.

ultimately, unless there is some type of chemical exposure or some type of emergency I don’t think that doing water changes is the answer.

that being stated I am also running a system that is 200 gallons of water which makes them cost ineffective.

for smaller systems this may be the best way to go.
I would be curious - if you take into account all of the equipment, testing, possiblity of system problems whether water changes are all that cost in-effective.
 

MnFish1

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You must be awfully sure about yourself, might want to think asking what he meant first ^^
It all depends on what he meant with "proper levels" and "long term pollution".

If "proper levels" mean "ocean levels", where the water has no accumulation due to the vast reservoir and natural filtering cycles, he is actually right. No amount of thinning, maybe short of something like 100% per day with continuous exchange, will bring pollution levels down to baseline.

If "long term pollution" means a constant accumulation of pollutants that the tank can't cycle itself fast enough, like nitrate without enough anaerobic bacteria and/or plants, no water change will get rid of the accumulation itself, it will only fight the symptoms (e.g. buildup).

At least that's as far as I understand ^^
You are not correct - at least not completely. If whatever you're trying to remove is produced more slowly than the amount being removed with water changes - the level of that chemical will eventually over time -trend to a stable amount - in some cases close to zero. That is 'math'. You can see it using any one of a number of water change effect calculators - here is one of them.

 
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Randy Holmes-Farley

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Please help me to understand. (I did read the article you posted, I love reading your stuff. I did have to google things to understand what they were.)

If the organisms we keep are intentionally secreting organics, and they will continue to do so, then how is the math on that organic removal not similar to using water changes to remove nitrate.

If anything wouldn't the organisms secrete greater amounts of organics as they grew larger?

When we do a water change of say 20% we would only remove 20 % of the secreted organics. The organisms would continue to produce more. The next water change would only remove 20% of the now higher number. So on and so forth. Eventually the secreted organics would rise to a level of toxicity. It might take longer then it would with the more commonly understood elements but wouldn't they eventually arrive at the same conclusion?

Also to clarify my stance on water changes as it seems to be misunderstood. I am not against them, but would not label a filter which needs several other filters, as effective. To many hobbyists read that all they have to do is change 10% of the water every week and their tank will be successful. I haven't found this to be the case. There is simply more to it.


Also, in personal experience I have kept systems for as long as 4 years in between water changes, only adding new water when water was removed fragging corals. My tank was full of corals, Monti's bigger then a basket ball, pagoda cup I could use as a lid to a bucket, all grown from the size of a quarter. IME I never ran in to a toxicity issue with DOMs (or POMs). Do you have any hypothesis on why certain systems can thrive without water changes for so long?

Thanks for taking the time to explain this to us.

It is very similar to removing nitrate. It is NOT true that they eventually rise to the same level.

Of course one has to make assumptions about accumulation rates vs natural degradation rates, but the graph i posted above is qualitatively suitable to see that after a year of 10-30% monthly water changes, the total material at the end of that year (as well as for most of it) is much lower with water changes than without, and always will be.

Im not sure how anyone knows whether the organisms in their tank are impacted by organics without testing it somehow, but folks can always fall back to “it’s good enough without it in my tank” without knowing for sure if it would be better in some way.

I’d also add that, assuming the effect is ever important, thst it matters greatly which organisms are in your tank, both as producers and potential sufferers.
 

MnFish1

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You should have taken simple math with the rest of us. Maybe I should have worded it differently. Water changes will reduce pollution but not eliminate it long term. Eventually the pollution levels will climb. They can not be solely relied on.

Funny enough I actually learned this from you in an article you did for Reefkeeping 15-20 years ago. I am going to round out the decimals to make it easier for us simple math people.

If your tank makes 10ppm of nitrate a week, and you do a 10% water change the tank still has 9ppm of nitrate left.

Week two the tank makes 10ppm of nitrate again, but there is still the remaining nine from the week before. So the nitrate is at 19ppm. That 10% water change gets you down to 17ppm.

Week three, tank makes another 10ppm of nitrate, and you had the 17ppm from before for 27ppm. A 10% change gets you down to 24ppm.

Week 4 tank makes another 10ppm of nitrate, add it to the 24ppm that was in the tank puts the tank at 34ppm nitrate. A 10% change brings the tank down to 31ppm

Week 5- tank owner posts on R2R asking why they have algae when their levels are perfect and they do weekly 10% water changes.

This same logic can be applied to using water at NSW levels to dose tanks, but in reverse.
Whether any chemical will accumulate over time or decline over time relates to the amount of the chemical that's produced with each water change as compared to the amount removed with each change. Take a look at these 2 graphs.

Basically your example above (Just change the production rate to 10 ppm): https://www.hamzasreef.com/Contents/Calculators/EffectOfWaterChanges.php
If you lower the production rate, You will get different results try 1 ppm or 0.5 ppm.

But - the bottom line if you plug in any number as the production rate - you will see that whether the level increases or decreases initially, eventually an equilibrium is reached - and the stuff you're trying to remove does not keep increasing infinitely. Your math above is not correct.
 
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Randy Holmes-Farley

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Whether any chemical will accumulate over time or decline over time relates to the amount of the chemical that's produced with each water change as compared to the amount removed with each change. Take a look at these 2 graphs.

Basically your example above: https://www.hamzasreef.com/Contents/Calculators/EffectOfWaterChanges.php
Using a different nitrate production rate:

But - the bottom line if you plug in any number as the production rate - you will see that whether the level increases or decreases initially, eventually an equilibrium is reached - and the stuff you're trying to remove does not keep increasing infinitely. Your math above is not correct.

Yes, and it is easy to determine what the long term equilibrium level will be. It plateaus when the input since the last water changes equals the amount removed in the water change. That level is well below the level without water changes (which does theoretically rise indefinitely).
 

pledosophy

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Whether any chemical will accumulate over time or decline over time relates to the amount of the chemical that's produced with each water change as compared to the amount removed with each change. Take a look at these 2 graphs.

Basically your example above (Just change the production rate to 10 ppm): https://www.hamzasreef.com/Contents/Calculators/EffectOfWaterChanges.php
If you lower the production rate, You will get different results try 1 ppm or 0.5 ppm.

But - the bottom line if you plug in any number as the production rate - you will see that whether the level increases or decreases initially, eventually an equilibrium is reached - and the stuff you're trying to remove does not keep increasing infinitely. Your math above is not correct.
That is a really cool calculator. Thanks for sharing that. I will play with it more.

When I plugged in a tank that accumulates 10ppm of nitrate a week it looks like with 10% weekly water changes I would expect my nitrate to be around 90 at the end of a year.

Even at .5ppm the nitrate is still increasing throughout the year.

Look at how much higher it is at week 16.

To me that is not an "effective type of aquarium filtration". I guess what is effective is a matter of opinion in some regards.



1660776628019.png
 

pledosophy

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That level is well below the level without water changes (which does theoretically rise indefinitely).
That is if you compare water changes as a filter to doing nothing at all. That does not compare water changes vs. other means of filtration. Yes doing water changes is better then doing nothing.

Water changes do remove pollution, are they effective at removing it what the prompt. To me it still does not look like it; although you have a very strong point about DOM's and POM's.

I think my conclusion thus far is somewhere around:

Water changes can be an effective way of removing specific organics from our systems that we can not test for, but they are not effective alone at managing nitrates, phosphates; or as a means of supplementing trace elements to a system if the source water used is at natural sea levels.

Does that sound fair or no?
 

flyfisher2

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I've read the post and here is my simple view. My tank had 50 ppm Nitrates. I began doing 30 gallon weekly water changes on the system which is roughly 150 gallons total volume. In the last three months I've gotten the nitrates down to 10 ppm. I'm not sure how much of that is being produced weekly but at this point the nitrates are dropping on average 1.5 ppm every week.Here's my math ( 10 ppm Nitrates X4 = 40 ppm. Divide 40 by 5 = 8ppm? Based on changing 1/5 of the tanks water volume.) I understand that method is not 100% but just like other filtration methods, ie. socks, skimmers ,refugiums, etc. Each one takes a portion. Call it filtration or dilution which in my eyes based on the methods we use seem to be one and the same. If we use a skimmer we empty the cup. If we use socks they need to be removed and washed. Carbon needs to be replaced, GFO as well. If we grow Macro algae it too must harvested. Something has to come out. I haven't seen a self contained system that is able to run in a bubble long term. Just my .02
 

LagoonParadise22

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I do a water changes every 2 weeks on average. About 15 gallons out of 80. A water change is a very effective method of filtration to the system. In nature water changes are done as well. Most people don't have a setup to really handle no water changes they simply just refuse to do a water change. But they definitely require it because there is no item that can truly effectively remove harmful toxins 100 % from the system . I've Personally notice after every water change fish breathe better and corals are more enticed to wanna feed as well . Basically after a well timed water change I always notice positive things . Water changes helped with algae as well . Must have a R.O.D.I system saves you so much time and effort. My water changes are no longer then 15 min . Get your self the best equipment possible you will love the hobby more if the job is easy .
20220623_152742.jpg
 

HomebroodExotics

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I do a water changes every 2 weeks on average. About 15 gallons out of 80. A water change is a very effective method of filtration to the system. In nature water changes are done as well. Most people don't have a setup to really handle no water changes they simply just refuse to do a water change. But they definitely require it because there is no item that can truly effectively remove harmful toxins 100 % from the system . I've Personally notice after every water change fish breathe better and corals are more enticed to wanna feed as well . Basically after a well timed water change I always notice positive things . Water changes helped with algae as well . Must have a R.O.D.I system saves you so much time and effort. My water changes are no longer then 15 min . Get your self the best equipment possible you will love the hobby more if the job is easy .
20220623_152742.jpg
I would argue that if changing 15% of your water makes your fish a lot happier then something is wrong with your tank the rest of the time. That’s not good imo. Or possibly it’s a placebo effect. I just have a hard time understanding why a 15% water change should make such a drastic difference. I’ve never noticed this even when I did water changes.
 

T-J

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what supplements are you using? thanks
This should answer your question:
 

LagoonParadise22

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I would argue that if changing 15% of your water makes your fish a lot happier then something is wrong with your tank the rest of the time. That’s not good imo. Or possibly it’s a placebo effect. I just have a hard time understanding why a 15% water change should make such a drastic difference. I’ve never noticed this even when I did water changes.
I would argue that if changing 15% of your water makes your fish a lot happier then something is wrong with your tank the rest of the time. That’s not good imo. Or possibly it’s a placebo effect. I just have a hard time understanding why a 15% water change should make such a drastic difference. I’ve never noticed this even when I did water changes.
My fish do not experience burning from the gills as if Ammonia is present in the system . Im speaking in general. I been in the hobby 5 years . All I'm saying is water changes does help with these animals health. The reason you don't notice a difference is because you're probably not doing it right or enough.
 

MnFish1

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That is if you compare water changes as a filter to doing nothing at all. That does not compare water changes vs. other means of filtration. Yes doing water changes is better then doing nothing.

Water changes do remove pollution, are they effective at removing it what the prompt. To me it still does not look like it; although you have a very strong point about DOM's and POM's.

I think my conclusion thus far is somewhere around:

Water changes can be an effective way of removing specific organics from our systems that we can not test for, but they are not effective alone at managing nitrates, phosphates; or as a means of supplementing trace elements to a system if the source water used is at natural sea levels.

Does that sound fair or no?
It is incorrect in part and correct in part. If you are doing - lets say 10% water changes - and keeping everything else the same - and your nitrates (for one example) - are rising - if you increase the percent or the frequency of your changes - you will eventually reach an equilibrium in which your nitrates are stable at a lower level.

not going to comment on whether using, for example, a turf scrubber or some other method of nutrient export is better or not. Only commenting on your statement that you cannot lower nitrates and PO4 over the long-term with water changes - its just not true.
 

all2insane

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Ghost25

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Regarding the aphorism, "the solution to pollution is dilution." The view that that was appropriate was responsible for considerable destruction of ecological habitats because industrial waste generators simply dumped hazardous waste into the water. After all, 100,000 pounds of highly toxic waste diluted in the ocean is effectively zero.

The Clean Water Act sought to remedy that and prohibited dilution as a means of waste disposal. Also see the rhyme-as-reason effect, rhyming sayings are viewed as significantly more impactful than non-rhyming sayings.

I know none of you are advocating dumping waste in the ocean, just thought it was interesting.
 

Randy Holmes-Farley

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That is a really cool calculator. Thanks for sharing that. I will play with it more.

When I plugged in a tank that accumulates 10ppm of nitrate a week it looks like with 10% weekly water changes I would expect my nitrate to be around 90 at the end of a year.

Even at .5ppm the nitrate is still increasing throughout the year.

Look at how much higher it is at week 16.

To me that is not an "effective type of aquarium filtration". I guess what is effective is a matter of opinion in some regards.



1660776628019.png

Obviously it depends on your definition of effective.

Is it effective to lower nitrate from 520 ppm to 90 ppm? That’s your exact example.

Many people, myself included, would say that drop is effective, even if it is not all the way to your likely target.
 

Randy Holmes-Farley

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That is if you compare water changes as a filter to doing nothing at all. That does not compare water changes vs. other means of filtration. Yes doing water changes is better then doing nothing.

Water changes do remove pollution, are they effective at removing it what the prompt. To me it still does not look like it; although you have a very strong point about DOM's and POM's.

I think my conclusion thus far is somewhere around:

Water changes can be an effective way of removing specific organics from our systems that we can not test for, but they are not effective alone at managing nitrates, phosphates; or as a means of supplementing trace elements to a system if the source water used is at natural sea levels.

Does that sound fair or no?

It’s certainly fair to have the opinion that if a filter method is not going to get you all the way to your goal, that it is not effective. I just do not share it.

In reefkeeping, we often use several methods at once, partly because none is perfect and they can complement each other in our attainment of many simultaneous goals.

In my reef system I used macroalgae growth in a refugium at night, large rock filled refugia, skimming, vinegar dosing, GAC, water changes by AWC, and GFO.

All of those, except perhaps the GFO, tend to lower nitrate. My final nitrate value was determined by all of them (plus ordinary organism consumption and food inputs).

Does it make them ineffective because none by themselves would have attained my goal?
 
BRS

Is there such a thing as an "easy" acro?

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  • Not sure

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    Votes: 3 1.2%
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