Dissolved Organics?

[scottward]

Dissolved Organics - organics meaning containing carbon - so does this mean Dissolved Organics is the same as DOC (Dissolved Organic Carbon)?

I've read a few articles about getting rid of dissolved organics, but nothing that specifically points out why.

If I understand correctly, some dissolved organics are good, but too many are bad.

If I understand correctly, dissolved organics bind metals - does this mean that too many organics somehow impacts trace element availability to plants?

I also understand that there is Dissolved Inorganic Carbon that the plants use. So DIC in whatever quantity is good - right? ;-)

Scott.

 

[Biollante]

Yes Pretty Much!


Hi Scott,

Basically you have it, yes.:gw

Biollante

 

[1077]

Dissolved organic's to me in tanks holding fish,is byproduct of fish waste from food's often rich in animal protein's.
With no plant's to take up these dissolved organic's, or over stocked tank's, then accumulation of these along with solid's,, = poor water condition's for fish depending on water changes, or lack thereof.
In heavily planted tank's,not so much a problem in my view.
Ditto for inorganic salt's,minerals, in plant fertilizer's KNO3,KH2PO4,CA,MG.

 

[Biollante]

Sorry I Get Going And... Well... It Is A Disease, I tell You, A Disease!


Hi,

As a matter of dissolved organics as opposed to particulate organic material, is any organic material smaller than 0.22, or 0.45, or 0.7, 2 microns, depending on where you look. Generally the organic material that can pass through a glass fiber filter of the appropriate pore size is considered “dissolved.” To be honest as a hobbyist, anything that gets through a coffee filter is generally close enough to follow along. Until recently I was a 2-micron type, now I have 0.7 and 0.45-micron capability.


Generally dissolved organic material, is used interchangeably with dissolved organic carbon (DOC), I think because it is easier to test for carbon and by definition anything organic, contains carbon. The organic material is of animal, plant and fungal origin, by definition it is all carbohydrate, lipid, protein, nucleic acid or some combination thereof.


At least in established tank most dissolved organic material seems to come from microbial activity. This is consistent with the “real world,” which if you think about it makes sense, if the material was broken down that far it is probably be some pretty small critters involved.


I think us hobbyists seriously under estimate the amount of biological activity and the sheer volume of critters that requires.


I have been poking around in the substrates and around the base of plants and various nooks and crannies; I can tell you there is a lot going on there.

In fact in mature systems anyway, there is more biological activity more oxygen use than in the main display areas.


Biollante

 

[scottward]

Thanks for the info Bio/1077.

So do you guys just vacuum the surface of the substrate where you can?

 

[Biollante]

It Is, Well... Complicated

Thanks for the info Bio/1077.

So do you guys just vacuum the surface of the substrate where you can?

Hi Scott,

The answer is complicated, it depends on what I am trying to accomplish, the condition of the tank, method of filtration, type of substrate and so forth.


If a deep sand bed is employed almost never. As a general rule the more mature the tank the less likely I am to do more than cosmetic vacuuming, in a mature tank most organic material is broken down quickly through biologic activity, this relates to higher ORP values.


Part of the cycling a tank goes through is something, sort of like, akin, to the microbial loop, when that is really moving along and some sort of balance is reached with protozoan and such grazers, the food chain established, the ORP values take on a certain stability to indicate a stability of the water conditions.



I have found consistency is perhaps somewhat more important than actual processes, so if you vacuum, continue to do so, if you do not and there are no problems, don't.


I don’t know if this helps.


Biollante

 

[ArnieArnie]

The sand in my 60 liter tank I don't vacuum. My shrimp will make sure that debris are thrown in corners and between plants or in the flow of the filter. I only change a little bit of water 20% once a month. DOC works like EDTA (same stuff water purifiers), it will capture harmful metals. Gravel would be more beneficial because debris can fall between it an I believe the biological processes happen faster there (surface area also much larger).

 

[1077]

In planted tank's, I have not vaccumed in nearly two year's.
In unplanted tank's holding fishes, I vaccum substrate.
Some foods offered don't worry me as much as other's.
Vegetable matter I offer pleco's has little animal proteins and so I feel comfortable leaving it in the tank longer, but pleco's also eat other food's and are large waste producer's so I feel better vaccuming the substrate for plant's don't do so well with them.
South American cichlid's eat foods rich in animal protein's and they too produce much Waste. Few plant's thrive in their tank's so I vaccum regularly.
Planted tank's I don't worry about. Snail's, Amano shrimp,corydoras, and plant's help keep substrate pretty tidy which suit's me.