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Organics Analysis

108557 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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Actually, I question that conclusion. Every time I've dosed CO2, whether it was consistent, non consistent, high or low concentrations I have never seen a clear cut relationship with BBA's growth (more CO2=no BBA) in any of my tanks at any of the various places I've set them up. Of course this is only observation with no numeric data behind it. If you look back at the results, you can see that in tanks with CO2 injection BBA is quite common, so I'd actually argue that CO2 has either no effect on BBA or it has a positive (helps it grow) effect.

This is the key I think. To figure out if the association between BBA is tighter with high TOC values or with CO2 use.
My experience is the same, Zapins. I've never had a reduction of BBA by increasing CO2. I have reduced BBA by lowering light levels however. I always figured that I was dosing too leanly, and the light was exhausting nutrients, causing imbalance, and thus algae, blah, blah, blah. I still think that's a piece of the picture. The thing I can't understand is some of the most stable algae-free tanks I've had are ones with some sort of soil or worm castings underneath a thick Aquasoil layer. I guarantee that the substrate is a dirty mess! Of course, it likely has all kinds of bacteria colonies that aren't in a clean commercial substrate. Or, on the flip side, the soil provides just enough nutrients to prevent the tank from bottoming out if I dose too leanly.
Niko, heck I have these kinds of tank disparities in my own fish room on a regular basis despite the same maintenance. It's frustrating!
This recent discussion takes me back 10 years to when we debated whether or not to add peat moss under the substrate or not. A quick googling bring up a very similar discussion.... In my fishroom, the only tanks that stay mostly BBA free are brand new Aquasoil tanks (for about 3-6 months, and then BBA creeps), and my farm tank that has wormcastings capped with old Aquasoil, running 5+ years as such.

Are any of you using peat moss/mulm under the more inert substrates like flourite, eco-complete, etc and noticing less BBA in those tanks?
That is my point of view too;) So for my new tank I'm working on how to optimize the heterotrophic bacteria growth and minimalize ammonia reduction and nitrate loss:)
Deep substrate beds?
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