Lets talk about water quality and waterchanges!

[zhuls1]

Ummm, you didn't give 1 piece of scientific information.

What is a dissolved organic? These are typically organic acids, e.g. citrate, iso-citrate, malate, succinate, etc., which serve as carbon substrates for bacterial growth. Dissolved organics are not a problem, because they lead to a bacterial population growth which consumes them.

you just contradicted yourself their, you said that dissolved organics isn't a problem, bacteria is. Than you go and say dissolved organics is what causes bacteria growth???

Filtration systems are not at all effective at reducing bacterial count unless yours have physical pores which are < 1 micron, the size of bacteria. There are no aquarium filtration systems that can do this other than the old fashioned diatomaceous earth filters.

Again, nothing scientific about that statement. No, you do not have to have physical pores < 1 micron, the reason for this is if you prevent bacteria growing in the first place, than their is no need to remove them. many filtration equipment do not remove bacteria, but rather prevent them from forming in the first place by outcompeting them for potential food sources. There have been countless studies showing exactly how effective many types of filtration are at reducing bacteria.

5. Protein skimmers work by physically removing dissolve protein via bubble formation. They have no impact on bacterial load.

Again, they remove dissolved organics, dissolved organics are what feeds bacteria growth in the first place. Aside from this, they also remove bacteria directly from the water column. Just search foam fractionation bacteria removal on google scholars and you will find plenty of studies showing its effectiveness on its removal. Also There are countless sources quoting the purpose of a protein skimmer as removing things like “water soluble proteins, amino acids, some organic dyes, fatty acids, fats, carbohydrates, tiny cells of algae, protozoa, bacteria and tiny buoyant particles of organic detritus, as well as other undesirable waste products” https://patents.google.com/patent/US5078867A/en

6. Nitrification is NO2 -> NO3, which is part of the nitrogen cycle. You probably mean denitrification, which is NO3 -> N2. Lots of folklore about that, but denitrification is an anaerobic process - so cannot occur when oxygen is present. Lots of nonsense on Youtube about setting about denitrification filters with no scientific rigor.

This couldn't be further from the truth. Please keep information factual and check the reputability of your sources. This is pure mythology caused from confusion behind the science of bacterial growth. Scientifically speaking, low oxygen levels know as hypoxic conditions is where denitrifying bacteria live. You probably have heard of anaerobic bacteria as being a bad bacteria that creates nitrites and should be avoided, hence why deep sand beds are considered to be harmful. However, other people refer to anaerobic bacteria as being a beneficial bacteria. The reason for this, simply it is confusion between types if bacteria and the environments that they live in. The problem is people refer to low oxygen level as anaerobic, and others refer to no oxygen as being anaerobic. I have personally read many studies on it and talked to experts in the field, including a limnologist and a marine biologist who majored in and studies bacteria. When it comes to anoxic conditions, the US geological survey defines it as being water below 0.5 milligrams per litre. This number does vary a bit depending on the source, but if you do a little research into the science fields you will find that this is where the heterotrophic bacteria reside, they can also reside in hypoxic conditions if the oxygen level is low enough. You say that no3 – n2 is how bacteria reduce nitrate level, but that could not be accurate. What happened to the other 3 oxygen atoms in your equation, and how did you get an additional nitrogen atom? What happens is anaerobic bacteria (Bacteria that lives at 0 mg/l of oxygen. cannot get their oxygen from the water source so they obtain it through their nutrient supply. So, no3 – 1 oxygen atom which the bacteria consumes = no2.

[zhuls1]

Also, wikipedia is not an accurate source of information as it can be created and altered by anyone. but since you are so fond of it for all your information, here is some articles for you to read https://en.wikipedia.org/wiki/Facult...robic_organism https://en.wikipedia.org/wiki/Aerobic_denitrification which says "Water treatment often relies on the activity of anaerobically denitrifying bacteria in order to remove nitrate from water.[5] However, due to the absence of oxygen, nitrate cannot be fully reduced to dinitrogen, thus nitrate remains in the water or it is converted to nitrous oxide.[5] Lingering nitrate in drinking water poses a plethora of health risks, and both nitrate and nitrous oxide have major environmental impacts.[6][7] Some hazards include, carcinogenic nitrate ions in drinking water, or eutrophication caused by oxidized nitrogen seeding Algal blooms.[5][8] Conversely aerobic denitrification can further reduce oxidized nitrogen in a less specialized environment."

[zhuls1]

https://www.nature.com/articles/s41598-017-09556-9 Interestingly, just a thought to share. I know someone who has had great success growing discus in a large, commercial fish farm pond. This pond did not recieve water changes, but rather operated via green water. He had growth rates faster than what he could accomplish in an aquarium.

[JamesW]

You and Willie are both right at least about the denitrication

Often times in chemistry and biochemistry an abbreviated, unbalanced equation is used to emphasize the overall transformation, i.e. NO3 to N2. The use of the full balanced equation is useful to process safety scientists and few others... Denitrification consumes NO3 and generates N2, the mechanism by which is likely varied and depends on the bacterial species performing the process. Willie also didn't say that was HOW bacteria perform denitrification, simply that was the overall transformation.

The standard oxidation potential for O2 is 1.23, nitrate 0.96 and sulfate 0.20. These are under standardized conditions but it is clear to see why life (in general) prefers to use O2 as the terminal oxidant for energy production. The will to live is strong for bacteria and when O2 is low and nitrate abundant, sneaky little bacteria start to use nitrate as the terminal oxidant for energy production. When denitrification filters go too far both oxygen and nitrate concentrations are too low, bacteria can start to use sulfate as the terminal oxidant which generates reduced sulfur species which are smelly and toxic to many animals.

Your argument is DOC are bad and there are ways to get rid of them:
Remove stuff before they break down into dissolved organic carbon by using filter socks to remove particulate
Remove stuff and DOC by using a freshwater protein skimmer
Carbon which is quickly over whelmed
An electrolysis system which seem to operate similar to an ozonator often used in marine setups

I agree with all of this.

I think there is another way and it is what Adam touched on regarding the mattenfilter. It depends on an fairly universal axiom that if you can make energy from it then there will be a bacteria that will eat it. You can argue the validity of this but I think it would hold true for the types of DOC's we observe in our tanks. Mattenfilters (and all biological media) operate via biofilms, diverse, resilient, complex, symbiotic, heterogeneous bacterial populations. Mattenfilters are notable for the size of the surface area suitable for biofilm formation. Now, whether or not it is enough to reduce DOC's to levels which don't impact Discus growth I don't know however in the same way that we seed filters with the right types of bacteria for the nitrogen cycle we might eventually be able to find the right types of bacteria to remove DOC's. I think seachem pristine and API ecofix are the first steps on the way to solving this in the same way we have solved the denitrification issue.

[zhuls1]

Hello James, I appreciate your input and agree with most of what you said. However, in regards to the matten filter, the problem is it catches waste, where it stays and can break down. Basically, whilst bacteria can reduce dissolved organics, it likely creates as much dissolved organics as it reduces. In addition to it catching organics preventing it from being removed by other means, the waste on the filter drastically reduces the filters efficiency effectively minimizing the surface area that nitrifying bacteria can utilise. But this could be overcome by regular cleaning like how we treat sponge filters. Perhaps that is why stendker reccomends a matten filter?

[zhuls1]

http://www.diskuszucht-stendker.de/g...s,index,0.html, Stendker uses them in their breeding operation, and they have been known to do very minimal water exchange. Maybe we need to be focusing on a very large aerobic surface area like what you would achieve in a matten filter? "The foam serves as the habitat for a vast array of microorganisms that include bacteria, archaea, worms, ciliates, flagellates, and many others." http://www.swisstropicals.com/library/mattenfilter/ Maybe the reason stendker reccomend so few cleanings of the filter isn't to prevent loss of bacteria but rather loss of other slower reproducing micro organisms?

[zhuls1]

When I argued against what Adam had said, I was not arguing against the use of the matten filter. Rather, I was arguing against the idea of leaving waste in an aquarium. I guess my focus was on mostly removing waste before it breaks down into DOC's, and I had not put so much thought into creating an environment which would encourage the removal of waste after they had became dissolved organic carbon. Sorry Adam, maybe you were onto something. I did not put much consideration into the micro organisms that thrive in biological filtration besides bacteria. I guess bacteria, algae and organisms such as copepods, daphnia etc are all beneficial and should be taken into consideration when comparing filtration methods. I had not realised that it would harbour these denitrifying bacteria, I had always assumed they would have to high of an oxygen level to be able to do that. Very interesting. Thanks for the info Everyone, it has been very educational. I do think discussions like this is ultimately what leads to advancements in the hobby. Has anyone tried running very large matten filters on their aquarium?

Also, in regards to products such as seachem pristine and API ecofix, I have heard of people using drain cleaners as they utilise the same bacteria and are much cheaper. personally, I prefer a more sustainable, balanced system approach that does not require frequent dosing of bacteria and/ or chemicals to maintain a healthy ecosystem.

[JamesW]

Great points Zac! In my sump I have 3" thick pieces of Poret foam going 10 - 20 - 30 PPM in fineness. The 30 ppm sheds brown heavy particulate that I vacuum out but otherwise I don't touch them and have noticed no change in the water resistance over ~6 months. I introduced copepods and can seem them wriggle through the pores of the 10 ppm foam but mainly they live in/amongst the seachem matrix I have right at the start of the sump and occasionally feed them to the discus. Same deal with red cherry shrimp I introduced into the tank and eventually they made it into my sump. They act as a buffer if I overfeed they will eat the food that gets down into the filter and then will grow/reproduce then I get to feed them to my fish!

I agree that the frequent dosing of Ecofix/Pristine isn't ideal. My point was more that once the nitrifying bacteria are established they don't need to be dosed. Maybe/hopefully/wishfully eventually the right kind of bacteria will be identified that break down the harmful DOC's and are able to establish a stable viable population in the filters. Occasionally I observe an oily film accumulate in my overflow. I simply wipe it with my finger and it gets sucked into my sump and I never see the oily residue in the return side of my sump so maybe...???

FYI just a plug for Poret foam and mattenfilter type setup. I'm a huge fan. Love the set it and leave it approach. It's worked out well for me.

[zhuls1]

What if, for example I was to create a hamburg matten filter for a 4 * 2 * 2 aquarium. However, I would place the sponge on the back of the aquarium, so I have a 4" span of sponge. Than, I would use a 30PPI sponge at the front and a 45PPi sponge behind it. Would than effectively have a slow flow through a massive surface area, could lead to some nice de nitrification happening?

[Adam S]

Going along the back would use a ton of foam. I'd favor a corner Mattenfilter, 10" radius with 3" 10ppi in front and 3" 20 or 30ppi behind it. This allows up to 180-360gph of flow through the filter, no more. Additional flow should come from powerheads/pumps.

Dimensions needed are 15.75" x (internal height of your aquarium) in 10ppi and 11" x (internal height of your aquarium) in 20 or 30ppi, plus two glass strips 1.5" x (internal height of your aquarium) in 3/8" glass. 1/4" might work, but that's a lot of foam/pressure. Ted Judy has a good video on YouTube on how to set one up.

Cheaper (and probably just a good) would be to just order a 3" corner Mattenfilter kit in 20ppi. $3.50 per inch of height on Swiss Tropicals.

Either way, it takes months for denitrifying bacteria to establish.

[brewmaster15]

I'm really curious about something here. D.O.C? Dissolved organic carbons? Though I do know they exist, and in theory I know they probably are in our tanks to various degrees. But with all this talk of them as a factor of water quality and discus, who is actually testing for them? What tests are you all using to quantify and qualify the types of D.O.C. found and what filtration methods are removing them? Playing the devils advocate here but it seems to me theres alot of assumptions on DOCs in our tanks being made but I haven't seen any hobbyist post test results. I'm not talking about some pHd scientist in a lab under controlled conditions with access to expensive HPLC/GC ms ,s etc equipment . I am talking about aquarium hobbyists like the ones on this forum and this thread. If you aren't testing for something how do you know you have it or more specifically how much of it you have or even what type? How do you know when something you do removes it? Sorry folks, but the scientist in me says we have the cart before the horse as far D.O.C.s and Discus Tanks or fish tanks in general.

I personally would love to have test kits for this stuff available so we could quantify and qualify D.O.C. effects and methods of removing them if they are something that negatively impacts our fish. We don't even know the rate the D.O.C.s increase in a tank or under what conditions they increase or are inhibited.

I feel like we have made D.O.C.s a boogey man or worse, a catch all acronym for everything that we don't fully understand about water quality.

I agree with Larry, Dan, Willie and the others here that change their water to reduce potential pathogens or chemical compound with Bad MOJO associated with them. The beauty of a water change is that it doesn't matter if you have D.O.C.s, or what kind they are. It doesn't matter if there are parasites, or alot of bacteria. You change the water and you remove them.Period. No science needed, no pHD, and you have the best water quality you can realistically and economically get.

Now I am not saying D.O.C.s aren't important, I am just being a pragmatist that for most hobbyists, they don't matter if people clean their tanks, take care not to overfeed, take care to stock realistically and don't skimp on the water changes. I would really love to see hard data on them on hobbyists tanks, but when I look at testing for them, its not looking like the technology is there for hobbyists kits? Am I missing something?

Al

[JamesW]

Not knowing your background Al but as a PhD scientist who works in a lab designing how drugs are made you are missing the earliest, most interesting (in my opinion) and best part of science.

For me the conjecture, curiosity and the 'I wonder if...' questions are what get my science motor revved up. It is the idea that if we can do X then we should be able to find Y and Z and do A through J. The actual execution I would, frankly, prefer an analyst or operator deal with...

Not to take words from Zac's mouth but his argument is that water changes help to grow the biggest and best discus but the defined culprit that is removed (or added) by this process isn't identified, which you also admit. Doing waterchanges removes things (nitrate, DOC's, bacteria, pathogens, bad JUJU, a disgruntled aura etc) and nitrate is convenient marker for this. I'm not sure if anyone has done the experiment but it would be interesting to see if large daily water changes were conducted with otherwise good water but with 30-50ppm nitrate dosed in and what the impact on growth would be.

I don't know the answer to that question but I suspect it wouldn't be as drastic as anticipated.

So if nitrate isn't the cause for growth inhibition in low WC tanks then what is? Zac idea is DOC's and he suggests ways that are alternatives to water changes that can be used to reduce them. Will this help to grow discus? Maybe?

You are right Al, we can't measure them and a water change is a great way to remove them and we don't even know if they are the root cause of the problem. However, if they ARE the cause of growth inhibition then why not ponder how to get rid of them without changing water? If a water change removes the toxins why even have a filter? Just use water changes to remove the ammonia being generated (I know some breeders do exactly this but it isn't a viable strategy for many).

There is great value in the 'If it ain't broke don't fix it' approach especially when there are living animals involved. However, beer was made before we knew about fermentation (there was a magical wooden spoon I think), same with cheese and wine. Even blood transfusions were performed before we knew about blood types. I think the same thing can be applied to the statement 'We can grow great discus by doing water changes'. It is true but wouldn't it be great to know why we can do it?

To borrow your metaphor the scientist in me thinks that for a horse to pull a cart, first you need to build the cart. Hell it might be the wrong cart but words are cheap and thought experiments and anecdotes are basically free.

[JamesW]

As an update: I think that Zac's initial post is a bit more didactic than I remember but the subsequent conversation has revealed the vagueness of the situation.

[brewmaster15]

Not knowing your background Al but as a PhD scientist who works in a lab designing how drugs are made you are missing the earliest, most interesting (in my opinion) and best part of science.

Hi James,
Im not missing it all and do feel much as you about it. I love the "what ifs " that go into science. Read all my back posts and you will find a ton. I do get it and love that part of science. I'm not a Phd by any means, just a humble biologist of sorts.I was trying to introduce a measure of reality check into the discussion. My point however was its hard to have an argument over who is right and who is wrong when there a lack of facts on both sides of an issue. You will note Im not saying these things aren't important. I think they are as important as all other aspects of fish keeping. But I would prefer to be able to measure what I argue about.

You mentioned you work in a lab designing drugs? Maybe this will help you and others understand my point. You are looking for a drug that treats diabetic complications. You have to have a way to measure the efficacy of your drug statistically by an invitro test before you can even try it invivo. You can make a thousand analogues of your drug but without a way to test it what good is it? If you are lucky someone took the time to develop assays for testing a particular biological process or pathway. You can now inhibit that pathway in something like a 96 well plate and using a plate reader you can tell which analogue works and which didnt. You can then test if the drug you made actually work and the fun begins. Until that point we had alot of ideas , now we can test them.

We need tests to test all the hypothesis and theories here and until then its a very interesting discussion, and could lead to something very insightful but its all conjecture to a large degree .

If we had markers for the D.O.C.s that we could measure that would be awesome.Its whats needed in my opinion to get an accurate picture of their effect or harmlessness in our tanks.


Ideally I would love to see someone with an interest in this come up with markers that could be tested.. I know its not likely but then there was a time when we didnt have hobbyist test kits for ammonia, nitrite and nitrates..

Hope you see my point.
al

[zhuls1]

I personally would love to have test kits for this stuff available so we could quantify and qualify D.O.C. effects and methods of removing them if they are something that negatively impacts our fish. We don't even know the rate the D.O.C.s increase in a tank or under what conditions they increase or are inhibited.

I feel like we have made D.O.C.s a boogey man or worse, a catch all acronym for everything that we don't fully understand about water quality.

I agree with Larry, Dan, Willie and the others here that change their water to reduce potential pathogens or chemical compound with Bad MOJO associated with them. The beauty of a water change is that it doesn't matter if you have D.O.C.s, or what kind they are. It doesn't matter if there are parasites, or alot of bacteria. You change the water and you remove them.Period. No science needed, no pHD, and you have the best water quality you can realistically and economically get.

Al

I would love to have test kits for everything too.

As for dissolved organics being a "boogey man" (love that term btw), you are not entirely wrong here. Dissolved organics is not a specific chemical, but rather it, either directly or indirectly, affects the health of the fish. As I mentioned it is not a single chemical, and each chemical effects the fish in different ways. The problem is their are many different DOC's and we can't possibly blame any single one of them on poor fish growth, rather it is a compounding effect of many different DOC's that cause problems. This is the reason why I can't blame a single DOC's for the lack of discus growth.

As for doing daily waterchanges, I have two comments on this. Firstly, if we don't experiment, we can't learn. We are ought to crack the code at some point. If we find the culprit that causes lack of growth, we can remove and or control it to maintain a healthy aquarium without the water changes. The second problem I have with your comment is that you say "I agree with Larry, Dan, Willie and the others here that change their water to reduce potential pathogens or chemical compound with Bad MOJO associated with them. The beauty of a water change is that it doesn't matter if you have D.O.C.s, or what kind they are. It doesn't matter if there are parasites, or alot of bacteria. You change the water and you remove them.Period. No science needed, no pHD, and you have the best water quality you can realistically and economically get."
Do we have definitive evidence that doing waterchanges offers the best water quality we can realistically achieve? To answer that, you would first have to know what good water quality is to begin with. How do we know when we are doing water changes we are not removing significant amounts of beneficial bacteria? And I don't just mean bacteria that filters the water, but I mean probiotic bacteria and other organisms.

Finally, many seem to be referring to bacteria and protozoans etc as the culprit, but their is, to my knowledge, no scientific evidence for that whatsoever.

Something that I would like to explore in the future would be green water. I have heard of people achieving faster growth rates than what they could achieve with water changes, and think it could be very educational. Not only do the micro organisms in greenwater remove dissolved organics, they also remove nitrogen, phosphates, bacteria and more whilst also offering the discus with an all you can eat buffet of live food.