Active carbon

[gemach7]

I'm still trying to understand why people classify AC as a "Chemical" LOL

Oh...DOC is the molecules where the N and P are bound up. Normally we have to wait for bacteria to break them down. Sometimes the bacteria cannot because the pieces are too big. That is where detritivores and micro fauna come in. Some people use skimmers to remove it before it breaks down. Some people use PP or HP to break it down chemically. The n and P and CO2 inside are not bio available until they are in there inorganic ions. Hence the interest in organics.

Now There's something I'd be interested in! A freshwater protein skimmer. No idea how they would do this given the much lower surface tension of freshwater, but maybe something involving high pressure mole screening of water creating smaller water droplets at time of air interaction to increase surface tension, not an engineer lol. But love the efficacy of these machines if plotted on a linear chart vs time compared to a regular filter.

Now caliban brought up a good point with TDS. Given that DOC is actually a measurement of dissolved and colloidal materials, wouldn't a TDS meter give a reasonable approximation of the organic material? Example if one tested the DOC and TDS of the effluence of different Rivers into the sea nature(where both would be highest) and plotted these linearly wouldn't a proportion arise? Thus with a readily available TDS meter tank owners would be able to see what is going on in ones tank with more accuracy as you are wishing to do?


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[jarrod0987]

Carbon, water changes, and uv sterilizers all do different things. While it is true some people have ways of keeping a healthy tank with fewer water changes than 50% weekly, it's not enough to make another blanket recommendation. And carbon and uv sterilizers instead of water changes isn't consistent with what I've heard from any established authority. Plants remove nitrates, a few non carbon filtration media debatably remove nitrates, but mostly fish keepers remove nitrates.

Good to know that getting tannins out might take daily changes of another quality of carbon. That would take more time than water changes, and sounds expensive.


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Sorry if I wasn't clear. AC doesn't really take out significant nitrates. It does take out DOC which is a broad category. It includes Tanins and also organic molecules that will eventually be broken down into Nitrates and phosphates by bacteria. Sometimes we can get them out before that happens. Another really cool thing I read in D. Walstad's book is that Tanins (AKA yellow water) bind to heavy metals making them non toxic. Then....IF you use AC, you remove those tanins and the heavy metals along with it. However plants eat Heavy metals too. Really getting way off topic now because DOC is such a wide range of compounds, waste water treatment people often do not bother to try to name or measure them all. They just figure out how much oxygen is needed to break them all down with bacteria and add just enough pumping to get just enough aeration. That is the whole BOD thing.

 

[jarrod0987]

Now There's something I'd be interested in! A freshwater protein skimmer. No idea how they would do this given the much lower surface tension of freshwater, but maybe something involving high pressure mole screening of water creating smaller water droplets at time of air interaction to increase surface tension, not an engineer lol. But love the efficacy of these machines if plotted on a linear chart vs time compared to a regular filter.

Now caliban brought up a good point with TDS. Given that DOC is actually a measurement of dissolved and colloidal materials, wouldn't a TDS meter give a reasonable approximation of the organic material? Example if one tested the DOC and TDS of the effluence of different Rivers into the sea nature(where both would be highest) and plotted these linearly wouldn't a proportion arise? Thus with a readily available TDS meter tank owners would be able to see what is going on in ones tank with more accuracy as you are wishing to do?


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Yes a freshwater protein skimmer would be nice but it doesn't work right as you stated. TDS probably would show these organics but It would also show a whole lot of other things. TO be fair these kind of meters usually only read things that have a charge when they are ionized and I'm not sure DOC's do? Out of my league on that one

 

[gemach7]

Yes a freshwater protein skimmer would be nice but it doesn't work right as you stated. TDS probably would show these organics but It would also show a whole lot of other things. TO be fair these kind of meters usually only read things that have a charge when they are ionized and I'm not sure DOC's do? Out of my league on that one

The conductivity tests, TDS meters, really only become grossly inaccurate when testing waters with a high proportion of inorganic salts that are ionically bound, hence no charge as a compound.

Also while thinking on this; I know ammano shrimp are popular in aquaria for the detrivore abilities, has anyone tried increasing the micro fauna in their freshwater aquariums? Ie freshwater Copepods or the like. I haven't just kinda popped in my head while writing this lol.


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[Caliban07]

Carbon, water changes, and uv sterilizers all do different things. While it is true some people have ways of keeping a healthy tank with fewer water changes than 50% weekly, it's not enough to make another blanket recommendation. And carbon and uv sterilizers instead of water changes isn't consistent with what I've heard from any established authority. Plants remove nitrates, a few non carbon filtration media debatably remove nitrates, but mostly fish keepers remove nitrates.

Good to know that getting tannins out might take daily changes of another quality of carbon. That would take more time than water changes, and sounds expensive.


Sent from my iPhone with three hands tied behind my back.

You could look at the nitrate/water changes topic another way where the aquarist is simply offsetting high nitrates either because they add them in the form of fertilisers, their tap water is high in nitrates, their bioload is too great for their tank, they are feeding too much, they don't use of have enough live plants etc. many NPT tanks where water changes are normally less frequent sometimes even fail to register nitrates.


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[Caliban07]

Sorry if I wasn't clear. AC doesn't really take out significant nitrates. It does take out DOC which is a broad category. It includes Tanins and also organic molecules that will eventually be broken down into Nitrates and phosphates by bacteria. Sometimes we can get them out before that happens. Another really cool thing I read in D. Walstad's book is that Tanins (AKA yellow water) bind to heavy metals making them non toxic. Then....IF you use AC, you remove those tanins and the heavy metals along with it. However plants eat Heavy metals too. Really getting way off topic now because DOC is such a wide range of compounds, waste water treatment people often do not bother to try to name or measure them all. They just figure out how much oxygen is needed to break them all down with bacteria and add just enough pumping to get just enough aeration. That is the whole BOD thing.

There are so many interesting facts like this in that book. One 'problem' I can see with with a build up of dissolved organics is the formation of surface bacteria. My betta tank has this because I don't have any flow. Instead I have a ton of floating plants with roots that are nearly reaching the substrate. Instead I use a small bubbler to break the surface for 15 minutes a day to prevent the surface biofilm from forming. I only have it on for 15 mins because my betta hides when it is switched on. Most of the filters that come with 5 gallon tanks are far to powerful for a betta IMO.


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[Caliban07]

The conductivity tests, TDS meters, really only become grossly inaccurate when testing waters with a high proportion of inorganic salts that are ionically bound, hence no charge as a compound.

Also while thinking on this; I know ammano shrimp are popular in aquaria for the detrivore abilities, has anyone tried increasing the micro fauna in their freshwater aquariums? Ie freshwater Copepods or the like. I haven't just kinda popped in my head while writing this lol.


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I have considered doing this myself. Some kind of substrate worm? Maybe some Copepoda or daphnia, a couple of snails of some kind, shrimp and a single betta. It would have to be a very mild tempered betta though for this to work.


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[gemach7]

I have considered doing this myself. Some kind of substrate worm? Maybe some Copepoda or daphnia, a couple of snails of some kind, shrimp and a single betta. It would have to be a very mild tempered betta though for this to work.


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My outdoor pond has lots of bristle worms. Tbh I don't know their effect on the overall quality of the water. Too many variables on that system, debris, rain fall, the fact I actually use a UV steriliser on that system, etc. That being said have no urge to collect them to test on a more closed system, seen too many people bit by them lol.


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