Why 10% & Can You Change Too Much Water?

[curiouser]

I do any and all calculations on tanks over the years with actual water volume.

Thanks, I assume this is what virtually every reefer does when calculating amount of an additive or salt.
But when a reefer says they did a 10% water change is the reefer saying actual water volume subtracting for the space (volume) of rocks and substrate?
Examples:
Water change for 100 gal tank with estimated 40 gal rock and substrate:
-When most reefers say they did a 10% water change did they change 6 gal or 10 gal?

 

[NY_Caveman]

Thanks, I assume this is what virtually every reefer does when calculating amount of an additive or salt.
But when a reefer says they did a 10% water change is the reefer saying actual water volume subtracting for the space (volume) of rocks and substrate?
Examples:
Water change for 100 gal tank with estimated 40 gal rock and substrate:
-When most reefers say they did a 10% water change did they change 6 gal or 10 gal?

Should be 6 gallons. Actual water volume, not tank volume, not manufacturer listed volume.

EDIT: I say should be because I do not know how exact people are. Anything related to water or water parameters should always be actual water volume which excludes glass, baffles, rocks, substrate and accounts for the water level.

 

[tiggs]

Yup, I do 20% weekly (skimmerless nano) going by actual water volume. I'm also incredibly anal about getting my new water to the same parameters as my system, since it's a decent percentage of the total volume. My salt mix mixes up lower than I keep my tank at in regards to calcium and alk, so I bring it up to the same levels.

 

[ca1ore]

You need to asking yourself why do water changes? If it is to get rid of nutrients, then you need to look at your sumps, skimmer, liverock, matrix, chaeto etc and your stocking and fedfing. If it is to replace other elements , you should conscons adding them.

I agree with this in principle ..... less so in practice. I do far less water change than I did a decade ago; maybe will do less a decade from now than I do today. The ability to truly measure the complete chemical composition of the water as yet eludes us; if at some point it does not then they may become unnecessary at all .... as a matter of routine, that is.

 

[ca1ore]

I say should be because I do not know how exact people are. Anything related to water or water parameters should always be actual water volume which excludes glass, baffles, rocks, substrate and accounts for the water level.

I suspect not exact at all. I actually wonder how many people actually realize that the vast majority of tank manufacturers 'rate' their tanks based on external dimensions. My current tank based on convention would be a 450 - but only actually holds 400 gallons (the remaining 50 being acrylic). Actual water displacement by the rock, sand, even growing corals, is hard to calculate accurately. Fortunately I don't think it really maters.

 

[NY_Caveman]

I suspect not exact at all. I actually wonder how many people actually realize that the vast majority of tank manufacturers 'rate' their tanks based on external dimensions. My current tank based on convention would be a 450 - but only actually holds 400 gallons (the remaining 50 being acrylic). Actual water displacement by the rock, sand, even growing corals, is hard to calculate accurately. Fortunately I don't think it really maters.

Right, and no one I bet checks how much water their rocks hold due to porosity. I think these are all things to be aware of, but it is not absolutely crucial to be exact to the drop for something like water changes.

 

[Jeff Evrard]

I do %5 a week and my corals are thriving. I am intrigued with doing a larger volume though. I will credit my success to a healthy micro biome and age of my live rock. 15 years or so in the system. Very happy. I will agree that even a tiny water change make the corals happy which is why I might try 10% then 15% and 20% . The only drawback I can see is that in this hobby it is prudent to err on the side of less of everything is better to minimize falling over the razors edge.

 

[Jeff Evrard]

I do %5 a week and my corals are thriving. I am intrigued with doing a larger volume though. I will credit my success to a healthy micro biome and age of my live rock. 15 years or so in the system. Very happy. I will agree that even a tiny water change make the corals happy which is why I might try 10% then 15% and 20% . The only drawback I can see is that in this hobby it is prudent to err on the side of less of everything is better to minimize falling over the razors edge.

 

[Scott Campbell]

The right conditions are required to fuel a bacteria bloom. There are many factors that can play a roll. Oxygen content, temperature, the presence, or lack, of competing organisms............. Arguably, the one, most important factor, is the availability of nutrients. Simply put, you can not have a bacteria bloom unless there are nutrients present to fuel it.
If you take a BB tank, where food is regularly added to the water, fish and other organisms are constantly defecating and releasing nutrients into the water, and organics are breaking down in the rocks to release nutrients, there will always be nutrients available. In such an established system, bacteria blooms are rare due to filtration, and the number of organisms present that utilize those nutrients and keep the concentration from growing large enough to fuel a bacteria bloom.
Simply removing that water, along with the nutrients it contains, and replacing it with RO/DI water mixed with a reputable salt brand, can not cause a bacteria bloom. In such a case, the available nutrient level will decrease due to the water change.
During a tank move, there are many events that can lead to a bacteria bloom. How the rock is transported is a major part of that. Extremes of temperature, lack of oxygen, and lack of water, are just some examples of conditions that can lead to the death of organisms within the rocks. Any organisms that parish in the rocks, from microbes to pods and worms, or even sponges and coral, will decompose once the tank is set back up. Those decomposing organisms will release nutrients that are likely to fuel bacteria, or other unwanted blooms.
IMHO, if a bacteria bloom fallows a BB tank move and 100% water change, there are other factors involved than the water change itself. A properly carried out water change, regardless of how large or small it is, can not cause a bacteria bloom.
Peace
EC

What you are claiming is likely true if nutrients are the only factor limiting a bacterial bloom. But if something else is a limiting factor (like vanadium or molybdenum or whatever) and you suddenly add a bunch of what was missing with a large water change, why couldn't that trigger a bloom?

 

[OriginalUserName]

I have seen nano tank owners weekly change all of their tank water. I though that was a common thing to do.

I think part of that is that it's easy/cheap to do that on a nano and they often have less reliance on other types of nutrient export.


IMO, people worry too much about cycles. I've had my share of screw ups and the like over the years but I've never caused a major problem by doing a large water change. The only real issue is large changes in stability, but if you are considering a large WC then the problem you are fixing is possibly worse than the parameter swings.

 

[Elegance Coral]

What you are claiming is likely true if nutrients are the only factor limiting a bacterial bloom. But if something else is a limiting factor (like vanadium or molybdenum or whatever) and you suddenly add a bunch of what was missing with a large water change, why couldn't that trigger a bloom?

In order for trace elements like "vanadium or molybdenum or whatever" to be limiting, the major biological elements like, Carbon, oxygen, hydrogen, nitrogen, phosphorus, and sulfur, must first be available in adequate concentrations. When we're talking about blooms of organisms, like bacteria in water, elements like nitrogen and phosphorus are vitally important. Simply put, we can not have bacteria blooms without these biologically major elements. Even if trace elements like "vanadium or molybdenum or whatever" are suddenly available. Freshly mixed RO/DI water with a reputable brand of salt, will be virtually void of nitrogen and phosphorus. Meaning, this water can not support a bacterial bloom even though it may contain trace elements. The concentration of trace elements, to a potential bacteria bloom, is irrelevant if major elements are limiting, as they are in freshly mixed synthetic sea water.

In order to produce a bacteria bloom in properly mixed synthetic sea salt, we must first add major elements like nitrogen and phosphorus. Like I pointed out in my original post, there are events, or conditions, that can lead to the production of large amounts of nitrogen, phosphorus, and other vital elements during a tank move. Even if 100% of the water was changed. However, it can not be the new water, of a properly carried out water change, with its near zero nitrogen and phosphorus that caused it.

In the event of a bacteria bloom fallowing a tank move and 100% water change, the most likely culprit would be the break down of organics. Basically, something died during the move, or someone drastically over fed after the move.

Peace
EC

 

[Scott Campbell]

In order for trace elements like "vanadium or molybdenum or whatever" to be limiting, the major biological elements like, Carbon, oxygen, hydrogen, nitrogen, phosphorus, and sulfur, must first be available in adequate concentrations. When we're talking about blooms of organisms, like bacteria in water, elements like nitrogen and phosphorus are vitally important. Simply put, we can not have bacteria blooms without these biologically major elements. Even if trace elements like "vanadium or molybdenum or whatever" are suddenly available. Freshly mixed RO/DI water with a reputable brand of salt, will be virtually void of nitrogen and phosphorus. Meaning, this water can not support a bacterial bloom even though it may contain trace elements. The concentration of trace elements, to a potential bacteria bloom, is irrelevant if major elements are limiting, as they are in freshly mixed synthetic sea water.

In order to produce a bacteria bloom in properly mixed synthetic sea salt, we must first add major elements like nitrogen and phosphorus. Like I pointed out in my original post, there are events, or conditions, that can lead to the production of large amounts of nitrogen, phosphorus, and other vital elements during a tank move. Even if 100% of the water was changed. However, it can not be the new water, of a properly carried out water change, with its near zero nitrogen and phosphorus that caused it.

In the event of a bacteria bloom fallowing a tank move and 100% water change, the most likely culprit would be the break down of organics. Basically, something died during the move, or someone drastically over fed after the move.

Peace
EC

We're not talking about a bacterial bloom occuring in buckets of newly mixed water. We're talking about the possibility of a bacterial bloom in a tank after a major water change. The new water would not have any nitrogen or phosphorus, but the tank could easily still have sufficient major biological elements available to fuel a bacterial bloom after a water change. For the sake of everything else in the tank you would hope major biological elements are still available. Trace elements are certainly limiting factors on the growth of corals or algae - why not bacteria? It seems very plausible to me that a tank depleted of key trace elements could experience a bacterial bloom if relatively large amounts of those depleted trace elements are suddenly replenished. Bacteria is certainly opportunistic enough to take advantage of sudden changes in water chemistry. I am not sure it would be an especially common occurence - but I think it is a false statement to say it is impossible.

 

[Elegance Coral]

We're not talking about a bacterial bloom occuring in buckets of newly mixed water. We're talking about the possibility of a bacterial bloom in a tank after a major water change. The new water would not have any nitrogen or phosphorus, but the tank could easily still have sufficient major biological elements available to fuel a bacterial bloom after a water change. For the sake of everything else in the tank you would hope major biological elements are still available. Trace elements are certainly limiting factors on the growth of corals or algae - why not bacteria? It seems very plausible to me that a tank depleted of key trace elements could experience a bacterial bloom if relatively large amounts of those depleted trace elements are suddenly replenished. Bacteria is certainly opportunistic enough to take advantage of sudden changes in water chemistry. I am not sure it would be an especially common occurence - but I think it is a false statement to say it is impossible.

It's impossible without large quantities on nitrogen and phosphorus.

To blame the water change, you would have to show how water that is virtually void of nitrogen and phosphorus obtained an abundance of nitrogen and phosphorus. Where did these elements come from and how did they reach such high concentrations that they led to a bacteria bloom? What is it in the system that produces quantities large enough to cause bacteria blooms? Even if there was some trace element that was limiting prior to the water change, and was replenished due to the water change, we still have to explain how the system produced massive quantities of nitrogen and phosphorus. We removed all the old water along with the nitrogen and phosphorus it contained. The tank in question is BB, so that leaves the rocks and organisms within the system to produce the nutrients needed to fuel a bacteria bloom. How is that possible without a large die off, and subsequent decomposition of organics???

Lets say there was some limiting trace element that was keeping a bacteria bloom from taking place. Then we stripped the water of nitrogen and phosphorus, while adding the missing trace element. At this point, the bacteria bloom can not take place unless, and until, there is a large addition of nitrogen and phosphorus. Where did the nitrogen and phosphorus come from to fuel the bloom? I don't see how rock from an otherwise healthy system could suddenly begin dumping massive quantities of nitrogen and phosphorus into the water, without some devastating cataclysm taking place in/on the rocks. .

 

[Scott Campbell]

It's impossible without large quantities on nitrogen and phosphorus.

To blame the water change, you would have to show how water that is virtually void of nitrogen and phosphorus obtained an abundance of nitrogen and phosphorus. Where did these elements come from and how did they reach such high concentrations that they led to a bacteria bloom? What is it in the system that produces quantities large enough to cause bacteria blooms? Even if there was some trace element that was limiting prior to the water change, and was replenished due to the water change, we still have to explain how the system produced massive quantities of nitrogen and phosphorus. We removed all the old water along with the nitrogen and phosphorus it contained. The tank in question is BB, so that leaves the rocks and organisms within the system to produce the nutrients needed to fuel a bacteria bloom. How is that possible without a large die off, and subsequent decomposition of organics???

Lets say there was some limiting trace element that was keeping a bacteria bloom from taking place. Then we stripped the water of nitrogen and phosphorus, while adding the missing trace element. At this point, the bacteria bloom can not take place unless, and until, there is a large addition of nitrogen and phosphorus. Where did the nitrogen and phosphorus come from to fuel the bloom? I don't see how rock from an otherwise healthy system could suddenly begin dumping massive quantities of nitrogen and phosphorus into the water, without some devastating cataclysm taking place in/on the rocks. .

It does not necessarily take "massive" amounts of nitrogen & phosphorous to cause a bacterial bloom. Nor a "devastating cataclysm". Sometimes it just takes a fortunate confluence of circumstances. A rapid change in water chemistry coupled with a lack of competition from other organisms able to take advantage of the new water parameters might be sufficient - despite a bare minimum level of nitrate and phosphate. People often experience bacterial blooms immediately after setting up their tanks even though the tank water is all newly mixed.

Again - I don't think it is a likely occurence. But I think it is certainly possible that a large water change which rapidly replenishes depleted trace elements might trigger a bacterial bloom. As some have noted happening to them in this thread. Which speaks to the initial post - why do smaller 10% water changes instead of larger water changes? The experience of most people is that smaller, more frequent water changes are not as risky.

 

[brandon429]

so far, just as in the "is detritus as bad as it seems" thread what's said so here far doesn't apply to small reefs at all. we're all keeping the same corals, many picos and nanos actually exceed large tanks on corals per gallon....so why does 3x 100% water changes not affect a coral only system nor ever cause a bac bloom on an SPS pico reef?



I think issues are sandbed keeping differences (cleaner sandbeds don't upwell nutrients with disturbance like in large tanks, pico reefers are keeping much cleaner beds vs old tanks from 90s design) and dilution. same for the detritus impact thread, this one is similar in scope and context.

why is it that for only large tanks, its debatable on water change frequency vs amounts but on smaller tanks, the more wc you do, the more you can feed, and the more live corals you have to keep dremeling out of the tank that never get sick? we get literally streamlined, perfect results in tiny tanks that use large wc and clean sandbed+ high feed approach.

facts on pico reefs --- google Maritza the vase reef to see the top pico I know of:

-never a bac bloom. Pico reefs cannot get bac blooms due to the way we run them and feed them, even if you don't do water changes correctly there wont be bac blooms, that's for large tankers (tbd why, I claim sandbed and additions meant to offset sandbed waste)

-no form of instability, the more you change water the better the system runs. Pico reefs respond best to the most water change freq and % you can stand to do, not the least. We're feeding just before, so the more you change water the more you are feeding and that's basic bodybuilers mass formula... def works on corals. *we didn't start off hands off then one day begin water changes above a bad sandbed...how many large tankers base their philosophy of water changes on that order of ops?

we started busy, and remained busy, and the coral rose to what was expected from the total ecosystem, total compliance from day one.

-when I look at Maritza the vase reefs 70 mo old vase, and then the best sps tank on this site, I see more fish and water obviously in the seven footer but I see more corals packed into the vase, it should be less stable. less accepting of alk changes involved in big water changes in systems of high command, but its not. Martiza is 90% water changes for 7 yrs.

and that's why large tankers can't make inferences about small reefs just yet, which are based on large percentage water change technique imo. its neat to insert outliers and see how they are factored into the graphing overall. we've turned massive water changes into the literal backbone of 10000 searchable tanks. I run multiple tank correction pm's at once across sites, and in 100% of them we are doing big water changes and making cloudy sandbeds clean.

 

[Elegance Coral]

It does not necessarily take "massive" amounts of nitrogen & phosphorous to cause a bacterial bloom. Nor a "devastating cataclysm". Sometimes it just takes a fortunate confluence of circumstances. A rapid change in water chemistry coupled with a lack of competition from other organisms able to take advantage of the new water parameters might be sufficient - despite a bare minimum level of nitrate and phosphate. People often experience bacterial blooms immediately after setting up their tanks even though the tank water is all newly mixed.

Again - I don't think it is a likely occurence. But I think it is certainly possible that a large water change which rapidly replenishes depleted trace elements might trigger a bacterial bloom. As some have noted happening to them in this thread. Which speaks to the initial post - why do smaller 10% water changes instead of larger water changes? The experience of most people is that smaller, more frequent water changes are not as risky.

I'm sorry but that's not how mother nature works. Let's look at phosphorus alone. Phosphorus is the backbone of DNA. Each bacteria could have 1 to hundreds of individual DNA strands. Multiply that by the millions or billions of bacteria in a "bloom" and you come up with a great deal of phosphorus. Without that phosphorus the bloom would not be possible. That's why it's a major biological element. It doesn't matter how drastically you change parameters or how many trace elements you dump in a tank.. You can not produce a bacterial bloom without large quantities of phosphorus. If you want to blame the water change for a bacterial bloom, you have to explain where the phosphorus comes from and how that phosphorus is connected to the water change.

 

[Stigigemla]

If You have neglected your tank for a while I dont recommend to change more water at a time than 10%. But do it every second day. Mix water - let it be til the next day and change. Make new water - temperate it and gas exhange 1 day - mix and wait 1 day. Continue until nitrate and phosphate levels are good. Expect increased algae and maybe bacterial growth because You are adding trace elements with the new water.
I have sold NO3PO4ex to a lot of customers but a bucket of salt works better and is safer to use. When nitrate is down to 10 ppm or lower you can change 20% without schocking the corals or clean up crew.