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Organics Analysis

108561 Views 450 Replies 29 Participants Last post by  Yorkie
The purpose of this thread is to (1) try to gather samples and data on the amount of organic pollution (i.e. Demand) that people have in their aquarium and (2) see if there is a correlation between the amount of organics measured (as TOC) and algae growth, specifically BBA.

The topic of 'organics' in the aquarium as a pollutant has always been very vague ... Often times, people talk about 'organics' as a problem in the aquarium but if you ask them about specific values of organics that cause problems or are acceptable or ask for specific articles about organic pollution level studies, most people are not able to provide any values or specifics. Instead they just wave their hands in the air and mumble generalizations like 'organics are bad and need to be as low as possible'.... how low is good? how high is bad? What are the average concentration values? Is there actually a correlation at all? That is the goal of this thread - to try to put generate analytical data on organic pollution (as TOC) and see if there is indeed a correlation between TOC concentrations and algae.

According to the Standard Methods Handbook, there are many ways to measure 'aggregated organic constituents' or 'organic pollution'. COD (Chemical Oxygen Demand) is the most common method of measurement and is defined as the amount of a specified oxidant that reacts with the sample under controlled conditions. Other methods of organic pollution analysis include BOD (Biologcial oxygen demand), TOC (total organic carbon) and TOD (total oxygen demand).

I would like to gather and analyse samples for organic analysis for their TOC content in order to see if there is indeed a correlation between the TOC of a particular aquarium and the presence of algae, specifically BBA. I work for an environmental laboratory, one of the instruments we have is a TOC analyzer (total organic carbon). This is a machine that measures the carbon containing compounds in your water by converting the carbon to CO2 and measuring the CO2 via an IR detector. Basically, there are two steps. In the first step, the sample is acidified. This converts all the inorganic carbon (HCO3- and CO3--) to CO2 and the amount of CO2 is determined. This portion is the TIC (total inorganic carbon). In the second step, an oxidant is added to the sample to decompose all of the organic carbon to CO2 and, again, the CO2 is detected. This portion is the TOC (total organic carbon).

If you are interested in participating and sending me samples for analysis, I ask that you collect and label your samples with the following information:

Name, Date of Collection, Aquarium Name (if you have multiple aquariums, usually the size), BBA present or not, CO2 injection or not, Water change frequency (and when your sample was collected with regards to them)

Also, be sure to include a sample of your source water (tap, RO water, RO water reconstituted).

For convenience sake, please collect samples in a DOUBLE SEALED ziplock sandwich sized bag, ~1/4 to ~1/2 full. Remove as much air as possible from the bags and seal the opening with packaging tape (or any other heavy duty tape like duct (or duck) tape, not scotch tape). Place all of the water samples into a larger gallon size ziplock bag for extra protection in case the bags leak. If you need or want to collect multiple samples over time, please refrigerate all samples for storage in order to minimize the amount of TOC degredation. Please PM me for shipping information.

I will analyze the samples and organize the results into a table format so we can then all analyze the data. If you would like your data to be presented as anonymous, please just include a note with your samples and i will report them on this forum as anonymous (but i need to know the actual name in order make sure i receive your samples and for proper sample tracking.)

Disclaimer. This analysis is for personal use only and all results may not be used for compliance testing and monitoring or legal use. I will not be held responsible for sample shipping, sample contamination and any loses that may occur.
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Great idea! Subscribed! I would love to have my tanks tested, they would be great for comparison. I've 1 BBA tank, 1 clean and 1 always balancing at the edge. Unfortunate, I live in the Netherlands. Nevertheless, I hope lots of people send you samples. For all people sending in a BBA infested tank sample, make sure it is still growing. BBA can remain in a tank very long even when the water is clean IME.
It does happen in tanks with no substrate at all too;)
Dealer holding tank hopefully get lots of large water changes and are not likely to get it. Our lfs has WC's automated, never seen much BBA since. But before, the upper row with discus tanks where no substrate was, did get some BBA when the bottoms were not cleaned and they were fed too much. This is how I started to believe in BBA and organics/rotting.
I wonder if this algae has to do with the TOC level or if it has more to do with the toxic levels of copper in my tank water. I'd guess the copper, but we'll let the data pile up.
Although your copper is quite high, I can't believe that to be the case, simple because algae has a lower toxicity level for copper compared to plants. You can easily kill algae with copper, ask any pond owner... And to answer your next question right away: why isn't it killing the algae? I think the reason is because there are a lot of chelators in your aquarium. Coming from fertilizers and decaying plant matter. This way the copper isn't nearly as toxic (luckily for you!)

That being said, high TOC (low oxygen), seems to be in line with the results...

PS. I wished I had someone to test for TOC over here. I did have all the other parameters checked once (I ended up with 28 ppm NO2, so not sure how trustworthy these result were because all my fish did fine, we blamed anaerobic bacteria in the water sample) but no TOC or anything like it. Keep up the good work Jeff! And for anyone sending him water, perhaps include a few stems of the rarest or most beautiful plant you own, I think Jeff would like that!
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Is 5.6 TOC a "high" level? I think we need a lot more results. Look at Cavan's results, he has double my TOC and I don't think he has huge amounts of algae.
I'm not sure whether 5.6 is high, I was under de assumption 1 was super clean and 8 really polluted, but I can't find my source.

About Cavans tank, I think he has a thread going about trouble in his tank as well. I don't know whether it is the one from the sample. Second, when someone is using less light, he might get away with a high TOC, so I think you can't compare tanks just based on the absolute number.
I'm not sure you can necessarily correlate TOC and [O]. If you want to measure [O], you really need an oxygen sensor...
No, you're right, there is no hard correlation. I was thinking that to break down TOC, bacteria need lots of oxygen. But perhaps I was a little fast with my correlation.
His other thread:

He had a zinc toxicity which was stunting his plants. I don't think he really has algae issues as far as I remember.

If you can find info on TOC I'd like to see it, I haven't found much background info on it.
My bad!

About the TOC values. The average from my tap is 1.2 (1.0-1.3) mg/L. There is no legal maximum in the Netherlands, but for our rivers they try to keep a maximum of 4 mg/L by controlling the amount of TOC in waste water from sewers and factories.

@Jeff: "TOC may be broken down by micro-organisms, in the process consuming oxygen"
True but using a hobby test kit isn't really that accurate to begin with. With no digital read out you lose a good bit of accuracy simply because it is based on the human eye and matching colors on a card. I think at best its an approximation even with standards made up.

I wonder if you can make a standard up, then seal it and keep it for reference? Or will it degrade and change color over time? I seem to remember having a nitrate test kit in botany class that had small vials with different strength solutions in it that you compared the color to rather than a print out card.
The Hanna colorimeters are a good way to rule out the human eye. This way we the inaccuracy of the test kit is the only inaccuracy you have. (and it appears this can be quite a lot depending on the brand)

About the references. I tried this once, the PO4 didn't changed as far as I could measure. The NO3, was lower after a few weeks and it contained NO2. My guess was that anaerobic denitrifying bacteria got into the solution. Couldn't think of any other way how an inorganic salt solution changed. So make sure it is sterile! :p

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Diatoms are not algae (they don't photosynthesize) so they should not be taking up plant nutrients at all. They are dinoflaggelates and are said to be related to high silicates in the water, or high organics which they supposedly feed on. This is why they tend to disappear in new tanks as they mature (silicates are depleted and organics stabilize).

Speaking of silicates, is that something that could be added to future tests without too much trouble? It would be nice to know if that silicates = diatoms statement is true since it has been said around the hobby for decades.
Diatoms are classified as algae and many species do use light...

But I've noticed a correlation with silicate as well. which is not strange because their mantle contains a lot of silicate.

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Good catch, I meant to say the *dinoflagellates* we know as "brown algae" are not photosynthetic.
I hate to say this, but most dinoflagellates do photosynthesize. And just by the fact that they are always in the brightest place in the tank and not randomly scattered all over (even in dark corners) I would say they do. Still I would love to see whether silicate is correlated to diatoms so if you could test that Jeff, I think you are a aquariumhero:p

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Let me add a nice example. A tank from a client runs for a year now without any algae. Low/medium light, CO2 and everything. He wanted angelfish. I advised adults because they need less food. He wanted small ones and feeds them twice a day to grow them to nice large eimekeis. Guess what happened in two weeks without changing anything else... BBA all over the place. He increased water changes to twice a week 50% and now BBA is barely growing. Keep the data coming Jeff, and all other info that is available. CO2 might be the answer for tanks were CO2 was not in balance with the amount of light and produce organics because of CO2 shortage. It isn't the answer for everything. Now the million dollar question, which organics? Sugars? Lipids? ... ? In 20 years I hope this is all commonly known and we laugh about this thread:p

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Hi all

What i have observed is Ammonia is a major reason for algae.. Perhaps the spores sense NH3 and start feeding.. Causes for ammonia could be very many: organics decay, plant damage, local rot, improper / under uasge of ferts or co2 all leading to imbalance in plant growths etc all start leaching ammonia locally. For eg a damaged leaf triggers algae on that leaf which then starts to spread.

Perhaps one needs to factor in this in the discussion?

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This is one often mentioned but I used a seneye monitor to monitor NH3/4. It didn't measure above 0.003 ppm. I did had a clear tank at the beginning and did had BBA, some GSA and some BGA after two months. When dosing ADA brighty lights, you dose way more NH4 daily and this off course doesn't induce algae.

I also used ammonia to cycle a goldfish rack. Dosing was way higher and no algae. So that is why the step before ammonia is now investigated, the organics that lead to NH4.

Jeff: do you think excel measures as TOC? Can you check by adding some excel to RO water and measure this for TOC?

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I'm pretty sure that excel is detectable in the TOC analyzer. We have a PAPAS meeting this weekend so i can pick up some excel from my local fish store and measure the change in TOC from a standardized dose. The real question, however, is how long dose excel last in the water column? That can only been done by dosing excel and then taking samples @ routine intervals over time.
I believe Tom Barr once said he had a glutaraldehyde test kit. I never saw the results though, but I'll check that tomorrow (its already late over here).

I used to work with a HPLC quite a lot. Unfortunate I don't have excess any more. Otherwise I would have loved to do some organics test myself.

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We all know that in the newly setup tanks there are usually huge algal blooms. The terrestrial substrate is flooded with water. Many chemical and biological processes take place in there. I would like to know if these algal blooms are also linked to higher TOC levels, or there is some other reason for blooming. What do you think?
In my experience yes! When using submersed plants, a cycled filter and inert gravel, you barely have algae blooms. When using organic based substrate or emersed plants (that loose their emersed leaves and leach organics into the water) or a filter without an established bacteria culture to break organics down, this is way more likely to happen. When all three are used, like a new ADA setup, the only way to reduce this change is to do daily water changes. Guess what they do... ;)

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I think aquasoil (I'm talking ADA) leaches organics in the beginning. Perhaps sequesters a little afterwards when nutrient are user, it but will become saturated quite fast.

I used different alternative brands of aqua soil like Fluval. This binds waaaayy more PO4 and is definitely less rich in nutrients so I think this has more binding spots for organics as well.

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That sums it up perfectly Phil!
Another reason not to use it?
I've recently stopped dosing glutaraldehyde and the empirical evidence suggests it does more harm than good to dose it. My plants are growing much faster now.
Me too! I stopped because I didn't feel comfortable that the toxic levels were so close to the beneficial levels for plants. Since than, I feel (sounds scientific doesn't it) plants grow faster and healthier. Fish are more colorful my Staurogyne finally took off (in two tanks!). So I only use my 5 gallon (sigh...) excel for cleaning diffusors and such.
Algae love CO2 just as much as plants. So increasing CO2 when algae proliferate on something else is stimulating them.

@Zapins: I think the CO2 BBA myth is coming from the fact that if your plants are CO2 deficient (not strange with the amount of light some people advocate), plants produce more organics. Increasing CO2 would in that case decrease organics, thus decrease BBA.
An interesting thought. It certainly seems that when there are a lot of happy plants there isn't a lot of algae. I wonder if that is because plants don't put out organics as you say, or if like algae plants can consume organics, or perhaps plants inhibit algae with allelopathy?
Plants consuming organics would be possible too. Would be a great source of carbon. Hard to digest perhaps, but still.
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