why do water changes?

[jda]

Just out of curiosity, what is the harder stuff that you say hardly can be found in any long term NWC tank?

It totally depends on each tank. If there were a group of for-sure specimens, then this would be easier. If you look at some of the tanks, they tend to lose the smooth skinned acropora and millepora and lots lose clams. I had a friend with a mixed reef that started to lose euphilya and acans after about 18 months when the BTAs, caulestera, some chalices and almost all softies did fine (he lost a huge colony of Space Monster Zoas, but they are not easy to keep) - he started to change water again and everything made a comeback.

My supposition is that it totally depends on which elements get built up and never get removed. These could come from equipment, food, etc. and everybody uses different stuff.

If any of you had to live in these boxes, I would bet that you would want a water change. I guess that some people might have never walked outside and smiled when they caught a breath of fresh air.

 

[jda]

Oh, I forgot about this one, but what about all of the people who dose 2 part. Will a buildup of Chloride Ions over time be troublesome? I do not know the answer here, just pondering. The few people that I know that do no/limited water changes all use CaRx.

With all of the known impurities in Kalkwasser, I hope that people who use a ton of kalk are doing some water changes.

 

[Sallstrom]

It totally depends on each tank. If there were a group of for-sure specimens, then this would be easier. If you look at some of the tanks, they tend to lose the smooth skinned acropora and millepora and lots lose clams. I had a friend with a mixed reef that started to lose euphilya and acans after about 18 months when the BTAs, caulestera, some chalices and almost all softies did fine (he lost a huge colony of Space Monster Zoas, but they are not easy to keep) - he started to change water again and everything made a comeback.

My supposition is that it totally depends on which elements get built up and never get removed. These could come from equipment, food, etc. and everybody uses different stuff.

If any of you had to live in these boxes, I would bet that you would want a water change. I guess that some people might have never walked outside and smiled when they caught a breath of fresh air.

Thanks!

I haven't seen any of that yet in the one tank tank at work that got it's last WC back in 2014. So thats one tank with the opposite results (so far) :)
Don't have any clams or zoas though.

 

[jda]

I have seen other people whose shrimp stop molting and die even with introduction of Iodine. Just out of curiosity, do you have any ornamental shrimp that are still thriving?

 

[Sallstrom]

I have seen other people whose shrimp stop molting and die even with introduction of Iodine. Just out of curiosity, do you have any ornamental shrimp that are still thriving?

No shrimps in this tank, just crustaceans like gammarus etc. There are some 10+ years old damsels that chases every new thing that goes into this tank. Usually they end up in the sump and then moved to a more peaceful tank. This happened the last time we added a couple of cleaner shrimps :)

Interesting observation though. Will have that in mind when reading about other NWC tanks.

 

[Lasse]

It totally depends on each tank. If there were a group of for-sure specimens, then this would be easier. If you look at some of the tanks, they tend to lose the smooth skinned acropora and millepora and lots lose clams. I had a friend with a mixed reef that started to lose euphilya and acans after about 18 months when the BTAs, caulestera, some chalices and almost all softies did fine (he lost a huge colony of Space Monster Zoas, but they are not easy to keep) - he started to change water again and everything made a comeback.

My supposition is that it totally depends on which elements get built up and never get removed. These could come from equipment, food, etc. and everybody uses different stuff.

If any of you had to live in these boxes, I would bet that you would want a water change. I guess that some people might have never walked outside and smiled when they caught a breath of fresh air.

How do you know it's not the other way around - something is missing?

With your parable of indoor and outdoor air - can you tell me what it is in indoor air that make you feel healthier and more alert when you open the window and vent.

If we should use probability. How do you know that just this part of the salt is perfect blended and not will give any issues? The uncertainty is as large here. and with weekly changes you risk this 52 times a year. Compare that with - something (unknown) can be built up during a year or two. For me it is clear that you need to use ICP testing in both cases and for me - it will be better not doing routine water changes and instead do changes (even WC) when the ICP test show that it could be a good idea.

If you do not know that your salt is exactly what it should be - the WC can become your sword of Damocles.

I do not do any regular WC and I use Triton Core 7

Sincerely Lasse

 

[Oshengems]

I was doing bi weekly Almost monthly the first 6 months but kind of stray away from water changes for the past year. Everything has remained more the same another note I was using a hydrometer which was faulty causing my salt to creep up but my tank is looking better than ever with by monthly 10% water changes just for the heck of it. One thing to keep in mind the amount of surface area in the tank I have my sump filled with LR the small pieces in the return chamber are filled!! With sponges which I know is the reason I can barely detect nitrates. I actually don’t test for it I see it in that area they get filled then next thing you now they are gone then they come back etc. I will say it’s duable just have a eye on your tank I’m running a 75g with 20g sump and about 120lb of LR there is surface area everywhere in my tank. Got one piece from an established tank filled with sponges and tiny feather dusters thus I I feel made a difference.

 

[shred5]

What about Allelopathy?
What removes this?
What test for it?

 

[Oshengems]

But just to note, no matter what!! not everyone has the same rituals, routines, rocks, Sand, lights, fish, tanks, sumps, salts heck not even water supply etc etc etc too many variables in this hobby. what works for some may not work for others i this hobby we tend to bash people tha step out of the “norm” or standard... perfect example you can still find people debating that LEDs are not good at growing sps now in 2018 When there’s clearly!!!! Undespisputed evidence that’s a lie how do they still argue this beats me, some people just have argumentive personality.

 

[jda]

Lasse, I do not know that something is missing, this could be totally right... There are a lot of swords that fall somewhere between a simile for the perils of power and Anduril, Glamdring or Longclaw that are plenty effective and better than not having one at all. I will go to battle with Instant Ocean... never let me down in over 25 years.

A lot of this comes down to experience and expectations. I have seen a thousand tanks, or more, and never seen one that did not do regular water changes that looked as good as those that do... if you want to argue small sample size, then cool. (this is why I am excited to see JB's tank in a handful of years since he has one of those elite level tanks) I am one of those who have never seen any LED lit acropora tanks that look as good as those that use other lights and they hit a ceiling at about 80% of what they could be, but I am over that ceiling and can tell the difference. What is Ok for some people is not for others. There are ceilings to every method... and if anybody wants to argue that most people never even reach the most basic ceiling, then I will not argue that either. Everybody is different, so better to point out too many differences than not enough... people can at least make their own decisions with too much to think about.

I will never argue that NWC is no good, just know what to look for in your research, notice what is missing (this is harder unless you have a ton experience) and set your expectations accordingly.

I sent off for 2 ICP tests and they told me nothing. I think that some people see them as a magic cure, but they often do not really tell any story that is worth testing... maybe some high lithium or low iodine (even though they do not tell you which form of iodine that they test for or what the levels of the other kinds are).

 

[Oshengems]

I really only do them to clean something, like vacuum the sand, or clean the overflow, or other things. I have done them also, to reduce aluminum levels. As far as using water changes to maintain chemistry, the only solid answer is, it depends on your tank. Nobody can tell you, for your tank that water changes is enough of an option for maintaining minor and trace elements. As JDA said, major elements (the top 3 for sure, calcium, alk, and magnesium) are almost always needed to be dosed on top of water changes.

After that, let’s say your tank consumes 10% potassium, well a 5% addition through weekly water change is obviously not going to cut it. Every week, you are losing 5% that the water change is not keeping up with, and thus you should dose. For some people, water changes is enough to maintain these elements, maybe they have less demanding corals, maybe they do larger volume water changes, maybe they do more frequent or automated water changes, maybe their salt has higher amounts of these elements, maybe they don’t actually know and are just assuming water changes is enough without actually testing. Whatever the case might be, only your tank will tell you what it needs.

It is no where near good enough for someone to tell you, just do water changes for minor and trace elements supplementation and don’t do additives. BTW, not all additives cost a lot, and also if your tank doesn’t need a lot of these elements. For example, I dose 5ml of iodine a week, a 250 ml bottle will last 50 weeks, at $7 per bottle, because it’s late, let’s just call that .60 cents a month. I can’t get anywhere near the above quote of $50 a month of additives, for everything. And I do between 5 or 10 gallon water changes a week, and it’s not enough for my tank for a few elements like potassium, iron, iodine, manganese.

On the flip side for nitrate and phosphate, the amount of water change it takes to make an impact on these numbers is usually very substantial. Let’s say your nitrate is 50 ppm. When you do a 10% water change, you still have 45 ppm nitrate after the water change, very little change. If you did a 50% water change, your nitrate is still 25 ppm. So, they really aren’t effective as a nutrient export solution on their own, so you have to supplement by using algae, protein skimmers, GFO, organic carbon, corals that are nice and big so they are consuming these elements, etc. Water changes never reduced phosphate alone for me, so I still had to run GFO for a while, and now I’ve moved to macroalgae.

Carbon does absorb some things, but not everything. This is the second area where water changes can help, as a tool in the toolbox. Let’s say your tin, or aluminum like for me, become elevated for whatever reason, a water change is the only way to restore elements like these back to proper levels. However, this requires that ICP tests are used, to give you the data that action needs to be taken.

If I narrowed a list, water changes are a good thing for staying connected to your tank, cleaning and working on the things you should, and reducing the elements that no other method can reduce. After that, maybe, only maybe, are water changes able to supplement minor and trace elements adequately. You would have to ascertain what your tank needs. For my tank, water changes alone are nowhere near enough.

I like your last note it is a good way to stay connected after the tank is established and on auto pilot the hobby gets a bit dull... another note I just thought about I do WC now when doing some maintenance to the tank

 

[jda]

What about Allelopathy?
What removes this?
What test for it?

People have anecdotally indicated that carbon could remove the organics, they could break down or they could get skimmed. While all of this is possible, I do not think that anybody really knows what happens. I know of no tests.

 

[Lasse]

What about Allelopathy?
What removes this?
What test for it?

IMO - Of no concern in the question of WC or NWC - weekly 10 % W will not hinder that. If it exist at all as real danger.

Sincerely Lasse

 

[Sallstrom]

People have anecdotally indicated that carbon could remove the organics, they could break down or they could get skimmed. While all of this is possible, I do not think that anybody really knows what happens. I know of no tests.

The only way to test what I know of so far is to try setup a tank yourself and see what happens :)
This is my experiment at work after four years without WC(but with a lot of Triton tests and additives).


Video by @Lasse

 

[vetteguy53081]

I Close my house up in the fall to prepare for winter. In the spring I like to open the windows to get some fresh air in the house.

Kinda the same thing if you were to never leave your house. I wouldn't want to live in stale air all the time.

To replenish elements and allow the fish fresh oxygenated environment. They are in a closed environment and expel waste and dropping. Although through the bacteria process corals absorb some of it as does filters, skimmer, carbon, etc.... Comparing it to taking a bath in the same water each day or hopping into an unfiltered swimming pool - we want to and generally purify the environment for clean/waste free exposure. Similar would apply.
I do water changes 1-3 times per year but allow the corals to indicate a sooner need by their appearance. My largest tank is on the Triton method which affords me seldom water changes.

 

[Mr. Limpid]

This from another site but is an interesting concept.
Fortunately, water changes are something that can be analyzed with math given a few assumptions. As opposed to more emotional arguments like how would you like to live in a bathtub with no water changes or water changes replace trace elements.
For the following analysis I am assuming something is in the replacement water. So let's call that “something”. Gee how original.
And something in the water is at a certain concentration of galloping elephants.
So this could be anything of any units of concentration. But let's also assume that galloping elephants is a linear measure unlike pH.
So you have a tank with some initial galloping elephants of something. And every so often you do a 10% water change. So after the first change you have 9/10s of the initial remaining. Second is 9/10s of that for 9/10*(9/10). the third (9/10)*(9/10)*(9/10) and so on. So that after sufficient water changes you have unmeasurable initial galloping elephants and the tank totally reflects the galloping elephants of the replacement water.
Simple. And what you usually hear here, at LFSs, in normal conversations and so on.
But now also assume that the tank has a constant change in something so that each day you have more or less galloping elephants. To analyze this case assume the replacement water has no galloping elephants. And to make analysis easier assume water changes are conducted at the same level and interval.
How much something is in the tank just before each water change after enough water changes have been conducted that we cannot measure the difference? In order for that to be true:
The amount of (between water change) change in something must be removed by the water change.
So if you do say 10% water changes, something must be 10 times the change. The water change then lowers the change to 9 times and something builds up again to 10 times just before the next change. 20% 5 times to 4 to 5. 33% 3 times to 2 to 3. etc. Mathematically:
just before water change=(change between water changes)/(fraction of water changes)
If you allow for some of something in the replacement water you combine the two effects:
just before water change=(change between water changes)/(fraction of water changes)+replacement water
If you “tie” the amount of water changes to the water change some interesting (to me anyway) results happen. Like 1%/day, 10%/10 days and so on. In that case:
Just before water change=(daily change*days between water changes)/(fraction of water changes)+replacement water.
Under those assumptions the following occurs:
days_____change__before_after___next
100______100%___100____0_____100
50_______50%_____100__50___100
33_______33%_____100__67___100
20_______20%_____100__80___100
10_______10%_____100__90___100
5_________5%_____100__95___100
1_________1%_____100__99___100
.5________.5%_____100_99.5__100
The limit of a continuous change at the rate of 1%/day you have a continuous 100 galloping elephants.
And to all those figures you add in whatever the concentration is in the replacement water. Both the before and after values are increased by whatever is in the replacement.

 

[beaslbob]

gee that kinda looks familiar. LOL

 

[Rolrod39]

I do 3 to 4 a year. That is it. I have a sump with refugium and don't have any issues. Also doing the balling method with Aquaforest components 123.

 

[beaslbob]

Oh, I forgot about this one, but what about all of the people who dose 2 part. Will a buildup of Chloride Ions over time be troublesome? I do not know the answer here, just pondering. The few people that I know that do no/limited water changes all use CaRx.

With all of the known impurities in Kalkwasser, I hope that people who use a ton of kalk are doing some water changes.

FWIW actually sodium and chloride do slowly build up. Sodium is from the sodium (bi)carbonate.
So there is a very slow build up of salinity. and when you add water to dilute that other tract elements are also diluted. Dr Holmes-farley stated that impurities in the material help a little bit.

 

[smartwater101]

Water changes, for larger tanks, are incredibly inefficient. Unless there is a problem element that needs removal.

That said, no amount of CUC is enough to clean the nastyness out of the sand so you better believe I'm going to siphon that s**t up every 3 or so weeks. Its a ticking time bomb so I might as well do a 10-20% water change while I'm at it.

But basically yes, it's to remove nutrients and introduce elements. It really just depends on on the size of the tank and your maintenance preference. 'Cause either way your going to be devoting a certain amount of time and money on either route.