Reducing water changes: methods, benefits, challenges & discussion

[NanoRox]

3 minutes ago, Clown79 said:

The one important factor is, when not doing waterchanges, it's very important to dose alk and ca as the more lps and sps you have, the more they will drop.

 

Test your tank after a waterchange for alk and ca. That would be your target numbers.

 

Test tank every day

 

Dose according to the drop from your target number.

 

So if your alk is 7.8 after waterchange, that's what you want to maintain daily.

 

Be careful with online calculators for dosing.

 

To date they have given me inaccurate quantities to dose.

 

 

 

If you are trying to keep alk at per say 9 but your salt isn't mixing at 9 and your tank after a waterchange isn't 9- trying to get it to 9 and maintain it is much more work and comes with fluctuations.

You'd need to dose your mixed water before the water change then dose to maintain.

All good info.  I dose ca and mg weekly in my ato.  Ca, mg and alk are not issues but you are correct I like to keep my alk at higher levels.  Dosing the refill sea water is a very wise suggestion.  I like my monthly routine now BUT will definitely dose-tweak my refill water as you mention.  Excellent suggestion!  

[empresto]

Another thing that may be of interest to some, and may also help answer the questions about how good this is for fish, is Diana Walstad's book on planted tanks (https://www.amazon.com/Ecology-Planted-Aquarium-Practical-Scientific-ebook/dp/B00DB94K5I/).  I know it is focused on freshwater planted tanks, but she sites several studies done with ocean plants as well showing the benefits of plants to their ecosystems and talks about how mulm and other organic compounds neutralize heavy metals and regulate other important parameters as well.  It's an interesting read even if you don't have a planted tank, though very much a text book feel.

 

My 23 gal tank (actual system water volume) has been running since the beginning of January, and I didn't do my first water change until toward the end of April.  I can't quite remember exactly when(though I could check my logs).  I do know that I nearly killed my montipora with that water change because my near zero nitrates went to much to much closer to zero for it to stay healthy and it bleached really badly.  Other coral in the tank went a bit pail as well.  After beginning to dose KNO3 via my ATO, the monti has since colored back up to about 85% of where it was and continues to look better every day.

 

As for algae, I've had some green hair-like algae in the display which has an anchoring-like root structure thing at the base.  This came on the live rock and I could have probably avoided it if I had bothered to clean it off before putting it in the tank, but I was lazy... 😞 However, it hasn't spread, and hand pulling some of it every month or so keeps it in check, so I'm not too worried.  Also, it is a great habitat for pods, and my tailspot blenny loves pulling at it and picking through it.

 

Personally, I think the algae in the display combined with the cheato in the sump helps keep the beautiful water quality I see in the tank and provides a lot of benefit that water changes wouldn't.  The results I see plus what I learned from Diana Walstad's book back up my ideas.  Plus, I'd rather thin plants than spend time and money on salt and RODI filter media. 😉 

[NanoRox]

21 minutes ago, empresto said:

Plus, I'd rather thin plants than spend time and money on salt and RODI filter media. 😉 

Amen to that!  We need to start a forum page here dedicated to fewer water changes in our nanos.  I say this half joking but honestly the nuances involved in achieving this goal is ripe for discussion.  

 

I will have to pick up this book or at least articles relating to it.  Would be an interesting read. 

 

You mentioned your monti.  I have a red monti and it is doing beautifully but I hadn’t thought about the .01 nitrate reading I have being less than ideal for it.  One more reason to slowly increase my nitrate levels.   I would like to achieve at least 1 

[empresto]

2 minutes ago, Duane Clark said:

You mentioned your monti.  I have a red monti and it is doing beautifully but I hadn’t thought about the .01 nitrate reading I have being less than ideal for it.  One more reason to slowly increase my nitrate levels.   I would like to achieve at least 1

I ended up over shooting on Nitrates with the KNO3 dosing (hit something over 4ppm), but I've been traveling a lot the last few weeks for work and didn't have time to test regularly.  The target I've been shooting for is to simply balance my Phosphate and Nitrate levels to the Redfield Ratio (https://en.wikipedia.org/wiki/Redfield_ratio), with my phosphates somewhere near .03 ppm.  I think there was also a BRS TV video where Ryan mentioned this ratio with regard to their nitrate dosing on the 160.  basically, this is the natural balance, and if these are balanced and in check, then things should be good.  Carbon is the third leg of this triangle, so if phosphate and nitrate rise together, then the system is probably carbon limited, and so on...  

 

+1 for your idea to have a forum page dedicated to fewer water changes!

[Subsea]

3 hours ago, seabass said:

I've been advocating that we should be dosing our tanks to target levels equivalent to a freshly mixed batch of saltwater.  That way, water changes do not cause wild parameter fluctuations.

 

Articles like that make me question just how much I really know about reefing, but a good article nonetheless.

 

@Subsea, how long do you think that it takes, for a tank to mature, before we see these interactions in our tanks?  I feel that many of us get too obsessed with killing algae with peroxide, using dry rock to prevent pests, and maintaining the sterile environment of a new reef tank, that we never see the benefits described in the article.  I've been making more of an effort to let my tanks mature, to increase biodiversity, and enhance the natural food chains.

 

 

 

Some of the biochemistry happens immediately.  Photosynthesis is where inorganic and organic chemistry meet.  Carbon dioxide as a free inert  gas dissolves in water and becomes carbonate & bicarbonate alkalinity.  Photosynthesis plus inorganic alkalinity equals glucose which is a carbon source for the ocean, as well as your reef tank.

https://en.m.wikipedia.org/wiki/Oceanic_carbon_cycle

 

@seabass

 

With respect to a tank mature time frame,  If I was to pick a hard number, I would say 3-5 yrs minimum.  The research is getting very specific.  Macro giving off inhibitors to prevent fish grazing, changes inhibitors when in the presence of certain corals.  For maximum production, monoculture is the easiest.  In our reef tanks, we want lots of differrent stuff.  For me this hobby/passion is not about bells & whistles,  It is all about how this stuff works together.  The science of it.

[seabass]

I think there is real merit in this discussion.  Many of the ideas being discussed here, are absolutely vital to successful reef keeping (even if we are unaware of their presence, or unclear of the particular details).  I wonder though, if many of these concepts are independent of water changes.

 

I want to encourage this discussion; and I don't want to discourage people from trying to push the limits of water changes.  However, I believe that disclaimers should be made.  The people here, which are trying to use this method, are taking extra care to determine the needs of their tanks, and to track its parameters.  It isn't simply a shortcut method to reef keeping.  I'd hate for beginners to see this and come away with - that water changes are not required (without making any other changes).

 

In some cases, we can disrupt our systems with water changes.  Whether that is from a sudden change in water parameters, or a release of organics due to a disruption of the substrate, or something else.  Removing these disruptions can often provide immediate short term benefits.  However, many people have gone down this road before.  Simply ignoring maintenance often has longer term negative repercussions.

 

There are financial benefits (especially in large reef tanks) to not having to change a lot of water; however, these are often counteracted by the increased costs of additives and testing.  As the size of the tank increases, the testing costs (per gallon) go down.  And often, as we become aware of our tank's needs, we can reliably predict consumption rates and how much we need to dose (testing only occasionally to make sure that we are not trending one way or another).

 

Anyway, I'm not sure that a 10% weekly water change actually causes the chaos that some make it out to.  As long as we are maintaining stability, we shouldn't be causing stress to the system.  However, that's not saying that these water changes are required; which is the point of this thread.  I just want people to understand what we are actually talking about here.

[Subsea]

I have had this discussion with PaulB about not doing water changes.  Twice a year, he does a 50% water change.  Paul’s tank has been set up for 45 years.  

 

For many newbies, the peer pressure of SPS and hi-tech overshadow the fact there is a lot of biochemistry going on in our tanks.  

 

Research data shows that protein skimmers & UV sterilizers strip out free swimming bacteria from bulk water.  What does that mean long term?  Considering that 60% of food energy in a reef is in the “microbial loop”, if I strip out the bacteria that transfer this food from one trofic level to another, then I interfere with live foods webs from feeding  the tank.

 

I do not consider nutrients in tank as bad.  I do not agree with “dilution is the solution to pollution”.    As with everything, it is a question of balance and personality.  I don’t fret the small stuff.

[NanoRox]

1 hour ago, seabass said:

I think there is real merit in this discussion.  Many of the ideas being discussed here, are absolutely vital to successful reef keeping (even if we are unaware of their presence, or unclear of the particular details).  I wonder though, if many of these concepts are independent of water changes.

 

I want to encourage this discussion; and I don't want to discourage people from trying to push the limits of water changes.  However, I believe that disclaimers should be made.  The people here, which are trying to use this method, are taking extra care to determine the needs of their tanks, and to track its parameters.  It isn't simply a shortcut method to reef keeping.  I'd hate for beginners to see this and come away with - that water changes are not required (without making any other changes).

 

In some cases, we can disrupt our systems with water changes.  Whether that is from a sudden change in water parameters, or a release of organics due to a disruption of the substrate, or something else.  Removing these disruptions can often provide immediate short term benefits.  However, many people have gone down this road before.  Simply ignoring maintenance often has longer term negative repercussions.

 

There are financial benefits (especially in large reef tanks) to not having to change a lot of water; however, these are often counteracted by the increased costs of additives and testing.  As the size of the tank increases, the testing costs (per gallon) go down.  And often, as we become aware of our tank's needs, we can reliably predict consumption rates and how much we need to dose (testing only occasionally to make sure that we are not trending one way or another).

 

Anyway, I'm not sure that a 10% weekly water change actually causes the chaos that some make it out to.  As long as we are maintaining stability, we shouldn't be causing stress to the system.  However, that's not saying that these water changes are required; which is the point of this thread.  I just want people to understand what we are actually talking about here.

Goodpoints @seabass.  I tried to make the thread title appear to not endorse one method over another.  I would love to keep this discussion going with the understanding of what we are discussing Suggestion on what I should change the discussion title to so as to not cause confusion or harm? 

[NanoRox]

24 minutes ago, Subsea said:

I do not consider nutrients in tank as bad.  I do not agree with “dilution is the solution to pollution”.    As with everything, it is a question of balance and personality.  I don’t fret the small stuff.

I have come to this conclusion myself...or at least am in the process of doing so.  I know frequent water changes Make up the general line of thought today (especially with nanos) but if we are to look at this as a kind of chemical art, I like the challenge of finding equilibrium within our tanks.  Certainly not saying this is the best way but there is a segment of hobbyists who I think like to explore the possibilities.  

[seabass]

Suggestion on what I should change the discussion title to so as to not cause confusion or harm?

IDK, maybe something like - Reducing Water Changes: Methods, Benefits, and Challenges

[Subsea]

Some people will be bedazzled no matter what the title is.  With the exception of the beginners forum, we are all reefers.   Let reefers read, discuss and reasearch.  I like it like that.

[1891Bro]

All this testing, dosing, and reading sounds like more work than a waterchange. Yes, that’s how lazy I am. 

[Subsea]

@seabass

 

With respect to water changes being costly on large system, but being of necessity because of trace mineral replacement as well as alkalinity management, I say that is not so in my systems.  I use aroggonite substrate to promote passive dissolving of minerals when pH drops during lights out, just as pH drops on the reefs in the oceans.  With the use of a calcium reactor, both alkalinity & trace minerals are added.  More importantly, recent studies show that carbon dioxide grows coral  and organaic carbon source like vodka grows bacteria.  Because we can’t test for complex DOC & DIC hobbiest do water changes.  I use GAC and cryptic sponges.

 

Do I think 10% change onec a week is going to hurt a system?  Worded that way, the answer is no.  Is it necessary?  That is the right question.  It is in your living room.  If you think it is necessary, it is your time management.  Do I think it is necessary?  The answe is no.

[NanoRox]

2 minutes ago, Subsea said:

With the use of a calcium reactor, both alkalinity & trace minerals are added.

I have not really dedicated much time to calcium reactors yet.  I understand their general purpose but need to research them to understand better their benefits /risks (if there are any risks).  In my little setup I am afraid I am cabinet limited.  

[Subsea]

2 minutes ago, Duane Clark said:

I have not really dedicated much time to calcium reactors yet.  I understand their general purpose but need to research them to understand better their benefits /risks (if there are any risks).  In my little setup I am afraid I am cabinet limited.  

You have aroggonite substrate which will give you passive aroggonite dissolving.  I would not consider calcium reactor on anything less than 100G.

[seabass]

2 hours ago, Subsea said:

... but being of necessity because of trace mineral replacement as well as alkalinity management, I say that is not so in my systems. ..

 

Do I think a 10% change once a week is going to hurt a system?  Worded that way, the answer is no.  Is it necessary?  That is the right question.  It is in your living room.  If you think it is necessary, it is your time management.  Do I think it is necessary?  The answer is no.

I also believe there are other ways (besides water changes) to manage alkalinity ( in fact, water changes are fairly ineffective at replenishing consumed elements).  Although, I wouldn't necessarily recommend relying on low pH dissolving the substrate to supply alkalinity either.  And while water changes do slightly help to replenish trace elements, there are other ways to replenish these as well (like from feeding, or other supplements that contain trace elements).

 

I think that you might have misunderstood my disclaimer.  I'm not at all arguing against reducing water changes; I'm just saying that ignoring maintenance because others seem to be doing the same thing can lead to poor results.  It's a matter of what else you are prepared to do, and to some extent, how mature your system is, and even your experience level.

 

In both my 100 gallon tank, and my 40 gallon tank, my water changes are more a matter of maintenance (exporting excess organics, versus just changing a certain percentage of water in the column, or doing it primarily to replenish consumed elements).  I feel that these water changes aren't a negative (even if frequent water changes aren't absolutely necessary).  I get what you are saying, and don't necessarily disagree.  Yours is an unique voice on this forum, and I'm glad that you are here to express it.

[Subsea]

With experience comes the knowledge of what you can ignore and what you can’t ignore.  In many cases, I ignore algae that would be considered unsightly for a “clean reefer”.  The maintenance to clean this does not necessarily make the enclosed ecosystem more healthy.  

 

PSS:  To be blunt, you can do 10% water changes every day and still have a shit system.

 

Said differently, if you have to do a 10% water change once a week, then there is a an excess of nutrients coming in.  I use macro, herbivores and coral to sequester these excess nutrients in the water.  

 

When I frag and sell coral that is nutrient export.

[NanoRox]

@seabass expresses my approach to my water changes as well.  Again, I am talking about our nano environments since it is all I feel somewhat qualified to discuss.  IMO the “goto” make a water change advice is sound In most cases BUT for my purposes they are a means of nutrient export...not supplement replacement.  For this later purpose I think a steady dosing procedure is best.  If nutrient export is adequate without having to remove water then IMO that is the best course of action.  

 

With that said, I think the principles @Subsea writes about are spot on.  The challenge is applying processes that take advantage of these principles in small scale

[NanoRox]

6 minutes ago, Subsea said:

PSS:  To be blunt, you can do 10% water changes every day and still have a shit system

Lol this statement needs to be at the top of the forum!!!  Love it!  

[squamptonbc]

1 hour ago, 1891Bro said:

All this testing, dosing, and reading sounds like more work than a waterchange. Yes, that’s how lazy I am. 

 

Same.

 

I lean more towards fish so corals are secondary for me, and water change is simple and easy. I was thinking about dosing, but it makes my head hurt and I hate testing and I get enough growth to make me happy, not looking for a forest or growth where I find I am needing to frag all the time like some end up having to do, I just want a tank with some coral movement to compliment the fish. Everything seems happy, even the anemone which has doubled in size in under a month, although still small since it was tiny when I got it.

 

 

[1891Bro]

33 minutes ago, squamptonbc said:

 

Same.

 

I lean more towards fish so corals are secondary for me, and water change is simple and easy. I was thinking about dosing, but it makes my head hurt and I hate testing and I get enough growth to make me happy, not looking for a forest or growth where I find I am needing to frag all the time like some end up having to do, I just want a tank with some coral movement to compliment the fish. Everything seems happy, even the anemone which has doubled in size in under a month, although still small since it was tiny when I got it.

 

 

I’ve tested my tank about twice, both for ammonia in the first month or two. I tear salinity during waterchange and check the thermometer daily, I guess that counts as testing. Whatever. If I had a large system and changing water was some fifty gallon drum ordeal I’m sure I’d feel differently. 

[Subsea]

I have not tested water parameters in 30 years.  Of recent, when I had a new well dug to 1000’, I sent  in for analysis; ground water, recirculating  water 5 years in system with no water changege and dry analysis of Red  Ogo.  There were no surprises and I see no reason to change my methods.

[Subsea]

8 hours ago, seabass said:

I also believe there are other ways (besides water changes) to manage alkalinity ( in fact, water changes are fairly ineffective at replenishing consumed elements).  Although, I wouldn't necessarily recommend relying on low pH dissolving the substrate to supply alkalinity either.  And while water changes do slightly help to replenish trace elements, there are other ways to replenish these as well (like from feeding, or other supplements that contain trace elements).

 

I think that you might have misunderstood my disclaimer.  I'm not at all arguing against reducing water changes; I'm just saying that ignoring maintenance because others seem to be doing the same thing can lead to poor results.  It's a matter of what else you are prepared to do, and to some extent, how mature your system is, and even your experience level.

 

In both my 100 gallon tank, and my 40 gallon tank, my water changes are more a matter of maintenance (exporting excess organics, versus just changing a certain percentage of water in the column, or doing it primarily to replenish consumed elements).  I feel that these water changes aren't a negative (even if frequent water changes aren't absolutely necessary).  I get what you are saying, and don't necessarily disagree.  Yours is an unique voice on this forum, and I'm glad that you are here to express it.

While you might not rely on reduced pH to dissolve aroggonite and assist using  “Dynamic Equilibrium” of aroggonite solubility beginning at pH of 8.05, it has worked for me for 40 years.  No one doses for alkalinity in the ocean.  The natural dissolving of aroggonite buffers water on the reefs in the ocean  just as they do in my tank.  All to often, with the use of SPS, the alkalinity demand on the water is very high.   In that case, passive alkalinity bufferring would not be be adequate.

 

PSS:  Know this for certain,  when the sun goes down, the normal pH fluctuations on the reef in the ocean varies from 8.15 to 7.85.    At those pH values, aroggonite will dissolve sufficiently so that I  have not dosed my 25 year Jaubert Plenum tank once.

[seabass]

7 hours ago, Subsea said:

it has worked for me for 40 years.

That's impressive.  But I thought you also mentioned use of a calcium reactor.  While a reactor might not technically fit the definition of dosing, it's similar.  If not, how much sand do you replace?  Is there a certain grain size that is more effective?

 

If we are simply talking about chasing pH with buffers, I think a lot of people here, including myself, are on board with you about not doing that.  But if we are talking about passive alkalinity buffering (through the substrate alone) being adequate to replenish alkalinity and calcium demands of a reef tank containing a significant amount of stony corals, then this is something that I would like to learn more about.

 

7 hours ago, Subsea said:

No one doses for alkalinity in the ocean.

Can you just imagine what that would take?   But unfortunately, with the predicted acidification of the oceans, many people believe that in the future, the ocean floor isn't going to suitably buffer pH either.

 

7 hours ago, Subsea said:

All to often, with the use of SPS, the alkalinity demand on the water is very high.   In that case, passive alkalinity bufferring would not be be adequate.

I believe that this is what we are really talking about.  We can probably include LPS in this category as well, possibly even coralline algae.  The consumption rates of alkalinity, and calcium, and magnesium seem to be just too high (when we have a significant amount of stony corals and/or calcareous algae in the tank) to be replenished through passive buffering alone.  Then we rely on dosing to replenish this consumption.  Or am I missing something?

[NanoRox]

41 minutes ago, seabass said:

consumption rates of alkalinity, and calcium, and magnesium seem to be just too high (when we have a significant amount of stony corals

This!  Again keeping this to nano’s I don’t see how substrate can even come close to providing enough of these minerals etc to feed our corals.  the Ratio of corals   To water volume in our small tanks is so much higher than in the ocean I don’t think it’s possoble without dosing or water changes at the very least.   

 

I’m not an authority on this at all so just my opinion but it seems like a fairly obvious observation.  Again, larger tanks would be a different story that I can’t speak to.