Are water changes over rated?

[Seansea]

Done all recently minus the skimmer. Last skimmer was used was the 90s which is nothing more than a glorified mechanical filter requiring human action to remove that skimmed but does add aeration yet can't see where algae wouldn't easily solve that. Until I tested new lights with doubling light intensity and longer duration tank was humming on just carbon dosing which I later stopped and seemed denitrification finally matured as I no longer had algae issues in the display although kept same overfeeding schedule. No corals as I was testing decomposition. Yet as it pertains to that affected by food. All good. No WC for 2 and half plus years.

Absent the water changes, one stops throwing nitrates out with the bath water and allows it to replace alkalinity lost during nitrification. My alkalinity stayed at 9 and all I ended up testing as change in that which let me know nitrates bottomed out or excessive. Thinking now that since alkalinity not being consumed by throwing it out then replacement should be only that corals use. Have to believe dosing going to be easier yet haven't tested that but will soon as test tank back up an running. I procrastinate.

Ignoring the assumption coral warfare may persist or hydroxyl might create detrimental DOC there's the fact tank will be more stable as less chance of any element including salinity going off because replacement water wasn't set same as display. Can't imagine dosing being more complicated since now it should be purely based on consumption and change coming from growth which not expected to be so accelerated that weekly testing won't keep it dialed in. Absent new additions. Gotta believe past initial setup this becomes set and almost forget minus the periodic ICP to ensure elements consumed as assumed and increased for additional growth or new additions. Science indicates all elements don't have to be present at all times in exact ratios therefore there's buffer to get trace dialed in and simple enough to periodically test major elements and ensure those are on track.

Only one way to find out. Stop throwing water out. Doubt tanks are going to suddenly crash.

How many fish we talking? 3 in a 75? I have 23 fish in a 75g. And I feed heavy. That's alot of fish voodoo. My skimmer is set to wet and my scrubber needs pruning every week. But I tried not changing water for a few months to save some scratch and all my corals looked bad and cyano crept in. Back to 20% per week and my corals perked right back up and cyano cleared. There is no turning back for me. I will ALWAYS do.weekly water changes. That being stated I do hate them

 

[areefer01]

I will ALWAYS do.weekly water changes. That being stated I do hate them

Not sure how you do them now but you could always automate it or make it more simple to do. Since you said you dislike it. I can understand that feeling though as I'm still lugging buckets.

 

[Costareefer]

Underrated.

 

[violetjones]

I only do water changes when my nitrates creep up. Phosphate can easily be managed with removal media or dosing phosphate-e. I also dose trace, calcium, alk, magnesium, manganese, iodine, and carbon. I do ICP tests every couple months.

I feel like it is much more stable and I am very particular about my trace elements being at certain levels so water changes sort of throw it off. Like my brightwell salt has very low iodine (i sent just a icp of pure brightwell freshly mixed water. It actually removes iodine level from the system.

 

[Doompastew]

If all of my water parameters are spot on, and everything looks good, why would I disturb that balance with a water change?

 

[VintageReefer]

How many fish we talking? 3 in a 75? I have 23 fish in a 75g. And I feed heavy. That's alot of fish voodoo. My skimmer is set to wet and my scrubber needs pruning every week. But I tried not changing water for a few months to save some scratch and all my corals looked bad and cyano crept in. Back to 20% per week and my corals perked right back up and cyano cleared. There is no turning back for me. I will ALWAYS do.weekly water changes. That being stated I do hate them

I don’t even know how you are doing 23 fish in a 75.

I have 7 and it’s a happy peaceful coexistence.

I’m already feeding the equal of 3 cubes a day with 7 fish

I’m no WC and tbh I don’t fully know how the tank is so successful. I feel that the all for reef handles alk ca and trace, and as for filtration / nutrient control / water quality - this is handled by the algae scrubber + cryptic zone filled with live rock and sponge colonies. Display also has blue rope sponge colony growing and yellow ball sponge. Cryptic zone has several medium to large unidentified white sponge masses + blue rope sponge from pruning

Nitrates 6.5
Phosphates currently .4 - .5, recovering from a spike after trying new coral food (spiked me from .08 to .98 after using the food 3-4x in a week)

 

[Seansea]

I don’t even know how you are doing 23 fish in a 75.

I have 7 and it’s a happy peaceful coexistence.

I’m already feeding the equal of 3 cubes a day with 7 fish

I’m no WC and tbh I don’t fully know how the tank is so successful. I feel that the all for reef handles alk ca and trace, and as for filtration / nutrient control / water quality - this is handled by the algae scrubber + cryptic zone filled with live rock and sponge colonies. Display also has blue rope sponge colony growing and yellow ball sponge. Cryptic zone has several medium to large unidentified white sponge masses + blue rope sponge from pruning

Nitrates 6.5
Phosphates currently .4 - .5, recovering from a spike after trying new coral food (spiked me from .08 to .98 after using the food 3-4x in a week)

It's a challenge. Fish bring their own set of challenges aside from corals. But to me a real reef duplicating nature is packed with fish. Just got back from hawaii and one big ole pocilipora could have 50 fish just hanging around it. Just added 5.

The existing ones did not receive them well and my big ole orange shoulder tang swimming by sends them to the rocks and he's not even aggressive. But ehen I sit back and look at the tank with all those fish swimming around corals is def sweet

 

[Randy Holmes-Farley]

If all of my water parameters are spot on, and everything looks good, why would I disturb that balance with a water change?

Because they might look better?

 

[GARRIGA]

How many fish we talking? 3 in a 75? I have 23 fish in a 75g. And I feed heavy. That's alot of fish voodoo. My skimmer is set to wet and my scrubber needs pruning every week. But I tried not changing water for a few months to save some scratch and all my corals looked bad and cyano crept in. Back to 20% per week and my corals perked right back up and cyano cleared. There is no turning back for me. I will ALWAYS do.weekly water changes. That being stated I do hate them

Number of fish less relevant than feed input. For example, feed 20 fish once a day same per fish same feed input if feeding 5 fish four times per day same amount per fish.

Size of biological makes all the difference in allowing it to fully decompose all uneaten food and waste produced along with ammonia and nitrites later scrubbed by algae to remove nitrates or carbon dosing solving the same issue.

Balance trace elements via dosing and testing and water changes become less needed.

Imagine doing water changes to solve ammonia as was the case before filtration was utilized. How goldfish and betta were kept in bowls and now those kept with filtration. We are still doing that now to solve nitrates.

Water changes don't balance ions such as trace because all they do is correct amount removed. We still need to dose more trace. Unless performing large enough water changes which on large systems are not practical.

Could it be that you weren't adding enough trace during no water changes and why corals suffered. Without specifics it's hard to pinpoint it was just lack of water changes.

 

[Seansea]

Number of fish less relevant than feed input. For example, feed 20 fish once a day same per fish same feed input if feeding 5 fish four times per day same amount per fish.

Size of biological makes all the difference in allowing it to fully decompose all uneaten food and waste produced along with ammonia and nitrites later scrubbed by algae to remove nitrates or carbon dosing solving the same issue.

Balance trace elements via dosing and testing and water changes become less needed.

Imagine doing water changes to solve ammonia as was the case before filtration was utilized. How goldfish and betta were kept in bowls and now those kept with filtration. We are still doing that now to solve nitrates.

Water changes don't balance ions such as trace because all they do is correct amount removed. We still need to dose more trace. Unless performing large enough water changes which on large systems are not practical.

Could it be that you weren't adding enough trace during no water changes and why corals suffered. Without specifics it's hard to pinpoint it was just lack of water changes.

20 fish fed once a day is still alot of load compared to 3 fed once or even twice a day. I feed heavy 2-3 times per day because I have anthias and chromis but also when you have 23 fish in a 75g aggression is real. No matter the biofilter or clean up crew which I have alot of that is alot of polluted water. Gives me a chance to blow off rocks cut corals and polish water with my polisher.

As far as traces go I have to add alot. Scrubbers chew thru them. Not only do I dose all for reef I add isolmt and manganese to my ato bucket. It wasn't traces depleted it was polluted water causing problem

 

[Timfish]

Is it possible that employing sponges would resolve the labile DOC remnants of hydroxyl radicals on DOC? Are there perhaps other remedies to solve this? Point being for every reaction there tends to be consequences and best solve latter vs just giving up on that path.

For example, veggie filters solve low pH by removing excess co2 yet consume iron needed by corals which we can later dose to compensate vs not using veggie filters.

Path to zero water changes might bring out ingenuity or might not but I find it more productive to keep seeking answers vs just giving up and returning to those dreaded buckets. Auto not pragmatic for my living space.

Considering how dynamic reef systems are and the importance of maintianing healthy microbiomes and the conflicting roles of the various types of DOC and microbial processes, some beneficial for corals (some species specific) and some detrimental and how little we know I don't see how healthy balances can be maintained without water changes. It's the only way I've seen that ALL the different types of microbes and DOC, good and bad, can be removed in equal portions allowing, hopefully, corals to promote and maintain what's beneficial for them. Every other method only arbitrarily skews these processes one way or another. Your hydroxil radicals certainly don't as evidenced in my previous post on it (#239). GAC doesn't remove all types of DOC equally. Ozone can convert refractory DOC into biodegradable forms that promotes microbial growth risking the microbial imbalances shown to cause problems with corals but leaves ozone refractory types to build up if water changes aren't used. Carbon dosing promotes microbial growth by making the refractory types avalable to heterotrophic types (read oxygen depleting types). Skimmers clearly don't do that much and leave hydrophilic types behind so clearly are creating very skewed microbial counts. Until we can quantify all the microbial processes and DOC and maintain the right ones and suppress the wrong ones I don't see how reef organisms can be sustained for thier normal life expectancies without water changes.


Keeping any animal in cage or enclosure entails what many would label as tedious and/or distasteful maintenance. For aquaria I've found using buckets easy and straight forward even when I have limited room in front of an aquarium, 4 sq ft is more than enough for most tanks. And time wise I can do a 10 - 20 gallon water change in as many minutes. If that's so much a burden for you maybe you should look into keeping non aquatic animals.


Always seeking answers is an admiral objective. I've been seeking answers for as long as I can remember. It's why I'm always checking current research and try to correlate what I read together with my experiences keeping reef aquaria. Hopefully to keep them for the decades they are able to thrive.

 

[Timfish]

Sooo…don’t use ozone or uv long term?

IMO, it’s a stretch to draw such a conclusion.

I’m just trying to figure out what claim is being made in that post

I understand.

My bad! I should have posted refferences.

At Next Wave 2011 in Dallas, Charles Sprung in his presentation advised aquarists not to use ozone. Experiments done at the Steinhart Aquarium found it was impossible to maintain theraputic levels with the equipment available for aquarists.

This paper listed several potential problems with ozone use for sterilizing drinking water. From this paper:

"Ozone exposures required for disinfection and oxidation may result in the formation of undesirable organic and inorganic byproducts, including various disinfection byproducts (DBPs) and biodegradable dissolved organic carbon (BDOC) (von Gunten, 2003b, Wert et al., 2007). Ozonation has been shown to convert relatively refractory components of dissolved organic matter (DOM) into BDOC (e.g., aldehydes, carboxylic acids, ketones and etc.) without a significant decrease in overall dissolved organic carbon (DOC) concentration (Liu et al., 2015, Nishijima et al., 2003, Wert et al., 2007)."


So it seems to me the answer would be, no don't use ozone. There are multiple papers (post #190) showing problems arise with corals when excess labile DOC allows heterotrophic bacteria to utilize the refractory DOC (DOM) as a food source. Breaking the refractory component into labile forms that can then be used for microbes to proliferate without being able to verify how coral microbiomes are affected doesn't strike me as a good thing.

 

[rtparty]

If all of my water parameters are spot on, and everything looks good, why would I disturb that balance with a water change?

What is “spot on”? Who determined this spot on? How was it determined to be spot on and which test(s) is even accurate or reliable enough to make changes based upon?

If a 10% water change is changing your elements enough to disturb the balance, you need to pick a better salt.

 

[GARRIGA]

Considering how dynamic reef systems are and the importance of maintianing healthy microbiomes and the conflicting roles of the various types of DOC and microbial processes, some beneficial for corals (some species specific) and some detrimental and how little we know I don't see how healthy balances can be maintained without water changes. It's the only way I've seen that ALL the different types of microbes and DOC, good and bad, can be removed in equal portions allowing, hopefully, corals to promote and maintain what's beneficial for them. Every other method only arbitrarily skews these processes one way or another. Your hydroxil radicals certainly don't as evidenced in my previous post on it (#239). GAC doesn't remove all types of DOC equally. Ozone can convert refractory DOC into biodegradable forms that promotes microbial growth risking the microbial imbalances shown to cause problems with corals but leaves ozone refractory types to build up if water changes aren't used. Carbon dosing promotes microbial growth by making the refractory types avalable to heterotrophic types (read oxygen depleting types). Skimmers clearly don't do that much and leave hydrophilic types behind so clearly are creating very skewed microbial counts. Until we can quantify all the microbial processes and DOC and maintain the right ones and suppress the wrong ones I don't see how reef organisms can be sustained for thier normal life expectancies without water changes.


Keeping any animal in cage or enclosure entails what many would label as tedious and/or distasteful maintenance. For aquaria I've found using buckets easy and straight forward even when I have limited room in front of an aquarium, 4 sq ft is more than enough for most tanks. And time wise I can do a 10 - 20 gallon water change in as many minutes. If that's so much a burden for you maybe you should look into keeping non aquatic animals.


Always seeking answers is an admiral objective. I've been seeking answers for as long as I can remember. It's why I'm always checking current research and try to correlate what I read together with my experiences keeping reef aquaria. Hopefully to keep them for the decades they are able to thrive.

But what science do you have to support that in home kept aquariums only water changes worked? Similar to the never ending thread on Bolus the consistent argument being test ran with comparable systems where the only variable being Bolus strategy added or absent. Who's done that with water changes vs new reefing mentality of dosing what's missing?

Plenty of tanks run on Trident, Moonshiners or Dutch Reef maintained without water changes with trace and other elements dosed based on testing. Are we now to assume that these tanks all doomed because studies on the reef indicate that's expectation and many of these have ozone and or UV and might also been dosed with peroxide which might be new to me but isn't new to fish keeping.

Dream tank will be north of 400 gallons with no practical means of automating water changes and I'm not hauling that many buckets or placing large enough Brutes around it to allow for adequate water changes. Wife will make sure I don't should I suddenly get the urge I'm sure of it.

There's been no scientific proof presented that any detrimental elements such as DOC or coral warfare remnants are diluted fast enough in home aquariums based on exchanging water. Fact not all perform exact same water change percentages would support that not being adequate. Don't care about how one can calculate how much removed weekly equates to tank turnover without knowing how rapidly said concerns build up. That's like assuming water changes can support calcium and alkalinity alone. Perhaps a 5 gallon Pico where 50% easy enough but not what I'm planning built.

As for hydroxyls, this isn't new. Anyone running ozone or UV that has dosed peroxide has created hydroxyls. Can't just assume that water changes solved it. That's just guessing at best. Could be they dosed low enough it didn't matter but none the less I'm sure some have because that's becoming prevalent and not just in trying to solve undesirable GHA but solving display tank ich.

My question is about using sponges to solves DOC. Instead of just proclaiming something won't work perhaps best seek solutions that might. Day we stop trying is the day this hobby and others stop progressing because we chose to just accept defeat or stick to old habits because that's all we believe or trust.

Let's simplify this vs taking sides.

Can sponges remove DOC concerns both naturally occurring as well as those created by hydroxyls? Based on what I've read and understood it seems they can therefore perhaps with the advent of cryptic zone we find a strategy that ensure these no longer remain the hurdle to throwing those dreaded buckets away. Can't see anything other than DOC and undetectable coral warfare remnants being a concern.

 

[tekknow]

I don't want to do water changes either if at all possible! I have a 220g saltwater tank I bought a year ago. It has seven 1" to 2" long fish, 2 shrimp, 1 hermit crab, 2 big snails, and 2 little snails that disappeared under the sand on day 1. I gradually introduced the livestock over the year.

I also have 3 big live rocks, 1.5" of live sand, and a gallon of bioballs and m1 media. There is also 6 small volcanic rocks, 2 filter socks, and a narrow mesh of foam and carbon that the water filters over on its way to the return pump. I have not used a protein skimmer so far.

RODI/ATO keeps the water level even. I leave the light on for about 8 hours/day and the color gradually changes from bright white to blue as the day progresses. The temp is a constant 78 degrees F. An auto fish feeder provides some flakes in the morning, and I feed them some frozen brine shrimp and some pellets in the afternoon. I only feed a little at a time to prevent excess food from falling to the bottom.

The guy I bought the tank from said he hadn't done a water change in 2 years, and his tank was crystal clear with thriving hard and soft coral. I don't know if he did any dosing, or what his lighting type/routine was.

I accept that there is probably variability in tank health over time as trace elements get depleted, and if the livestock population changes. I plan to take a water sample to the local reef tank store every couple of weeks and chart the chemistry to see if I can spot any correlations with, admittedly subjective, observations of tank health. They measure Salinity, pH, Ammonia, Nitrite, Nitrate, Phosphate, Alkalinity, Calcium, and Magnesium. Is there anything else I should be testing for?

So far, I haven't done any water changes and the chemistry is remaining stable (knock on wood). It could be because there is so much water for so few fish and it is taking time for the pollutants to build up. Is there a canary in the coal mine I should be watching for to warn me that a water change is needed?

 

[apb03]

I don't want to do water changes either if at all possible! I have a 220g saltwater tank I bought a year ago. It has seven 1" to 2" long fish, 2 shrimp, 1 hermit crab, 2 big snails, and 2 little snails that disappeared under the sand on day 1. I gradually introduced the livestock over the year.

I also have 3 big live rocks, 1.5" of live sand, and a gallon of bioballs and m1 media. There is also 6 small volcanic rocks, 2 filter socks, and a narrow mesh of foam and carbon that the water filters over on its way to the return pump. I have not used a protein skimmer so far.

RODI/ATO keeps the water level even. I leave the light on for about 8 hours/day and the color gradually changes from bright white to blue as the day progresses. The temp is a constant 78 degrees F. An auto fish feeder provides some flakes in the morning, and I feed them some frozen brine shrimp and some pellets in the afternoon. I only feed a little at a time to prevent excess food from falling to the bottom.

The guy I bought the tank from said he hadn't done a water change in 2 years, and his tank was crystal clear with thriving hard and soft coral. I don't know if he did any dosing, or what his lighting type/routine was.

I accept that there is probably variability in tank health over time as trace elements get depleted, and if the livestock population changes. I plan to take a water sample to the local reef tank store every couple of weeks and chart the chemistry to see if I can spot any correlations with, admittedly subjective, observations of tank health. They measure Salinity, pH, Ammonia, Nitrite, Nitrate, Phosphate, Alkalinity, Calcium, and Magnesium. Is there anything else I should be testing for?

So far, I haven't done any water changes and the chemistry is remaining stable (knock on wood). It could be because there is so much water for so few fish and it is taking time for the pollutants to build up. Is there a canary in the coal mine I should be watching for to warn me that a water change is needed?

If you decide to not do water changes I would recommend to maintain a very low fish population. It would be wise to stay away from having too many tangs or messy fish like puffers. Feed light.

Also try to avoid more demanding corals such as Acropora. Stick to soft coral and LPS that's inexpensive. Keep the lights and flow lower to avoid too much algae growth to drain your nutrients and account for the reduced livestock to eat it all.

I would strongly advise against the above and do water changes though.

 

[GARRIGA]

I don't want to do water changes either if at all possible! I have a 220g saltwater tank I bought a year ago. It has seven 1" to 2" long fish, 2 shrimp, 1 hermit crab, 2 big snails, and 2 little snails that disappeared under the sand on day 1. I gradually introduced the livestock over the year.

I also have 3 big live rocks, 1.5" of live sand, and a gallon of bioballs and m1 media. There is also 6 small volcanic rocks, 2 filter socks, and a narrow mesh of foam and carbon that the water filters over on its way to the return pump. I have not used a protein skimmer so far.

RODI/ATO keeps the water level even. I leave the light on for about 8 hours/day and the color gradually changes from bright white to blue as the day progresses. The temp is a constant 78 degrees F. An auto fish feeder provides some flakes in the morning, and I feed them some frozen brine shrimp and some pellets in the afternoon. I only feed a little at a time to prevent excess food from falling to the bottom.

The guy I bought the tank from said he hadn't done a water change in 2 years, and his tank was crystal clear with thriving hard and soft coral. I don't know if he did any dosing, or what his lighting type/routine was.

I accept that there is probably variability in tank health over time as trace elements get depleted, and if the livestock population changes. I plan to take a water sample to the local reef tank store every couple of weeks and chart the chemistry to see if I can spot any correlations with, admittedly subjective, observations of tank health. They measure Salinity, pH, Ammonia, Nitrite, Nitrate, Phosphate, Alkalinity, Calcium, and Magnesium. Is there anything else I should be testing for?

So far, I haven't done any water changes and the chemistry is remaining stable (knock on wood). It could be because there is so much water for so few fish and it is taking time for the pollutants to build up. Is there a canary in the coal mine I should be watching for to warn me that a water change is needed?

Consider researching Triton, Moonshiner and Dutch methods as they rely on ICP to determine lack or excess of trace elements not detectable by hobby level kits. What I'm doing once main is up and will be testing once my 20g rebooted. Triton being the original but I'm gleaming all three as well as other sources of information and developing that which fits my life style and accommodations. I'm also going overboard with filtration which includes biological and plant based and now researching cryptic as a means of avoiding those dreaded buckets or garbage cans.

Only one way to find out. Just do it. Worse case, I keep fish with Shrooms and inverts. Still a reef tank. Not all need to be Sticks.

 

[goosemans]

Every tank I’ve managed over 24 years has no water changes in mind. My only failure was one of my first tanks that had a 6/7” dsb, and even that lasted 6+ Years

This tank was setup 8 years ago. There hasn’t been a water change in at least 4 years

Doesn’t look like an 8 year old tank

 

[areefer01]

At Next Wave 2011 in Dallas, Charles Sprung in his presentation advised aquarists not to use ozone. Experiments done at the Steinhart Aquarium found it was impossible to maintain theraputic levels with the equipment available for aquarists.

Steinhart aquarium is 212,000 gallons...

 

[areefer01]

Consider researching Triton, Moonshiner and Dutch methods as they rely on ICP to determine lack or excess of trace elements not

I do not believe that the DSR method by Glenn Fong uses ICP. At least from what I recall. They had a list of what elements to test and what test kits to use. Maybe that has since changed.