# Interesting Link re: BGA/Redfield Ratio



## Homer_Simpson (May 10, 2007)

Yes, this is not new I knew about this and have seen it before.
http://www.xs4all.nl/~buddendo/aquarium/redfield_eng.htm

For me, the ratio would only have practical "real life scientific validity" if it applied across the board each and every time. I currently have 5 tanks and have tested my phosphates and nitrates with calibrated test kits. According to this "Redfield Ratio" chart, all my tanks should have developed BGA, but only one did. And with that one 10 gallon, after I dosed Erythromycin, it pretty much vaporized never to return. The tank has been up and running for more than a year now, and based on the tested nitrate and phosphate levels, if you buy the Redfield Ratio chart, the tank should be showing a severe BGA outbreak, it is not. Bottom line, the ratio, at least IME fails the test of scientific validity and reliability.

No offense, but I believe that BGA is too complex a bacteria to be explained by the Redfield Ratio notion as it likely has a multitude of causes and it's occurence may be due to more than one factor so it may materialize in different tanks for different reasons.
Tom Barr has managed to promote the developement of BGA by purposely letting Nitrates bottom out and fall to zero. When I got it in my 10 gallon tank, my nitrates as tested with a calibrated test kits were really high, so I am not convinced that lack of nitrates will cause it in each and every case. I have also other tanks where nitrates are high and the nitrate and phosphate ratio as per the Redfield Ratio should confirm a BGA outbreak, but there is no BGA at all.


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## Hoppy (Dec 24, 2005)

Furthermore the Redfield Ratio refers to the ratio of nitrogen and phosphorus not nitrate and phosphate - they are different.


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## Homer_Simpson (May 10, 2007)

Hoppy said:


> Furthermore the Redfield Ratio refers to the ratio of nitrogen and phosphorus not nitrate and phosphate - they are different.


Interesting. So, how do you test for nitrogen and phosphorus. Are there test kits to specifically test for nitrogen and phosphorus vs nitrates and phosphates??

Edit: 

Okay, ran the Dutch language conversion instructions listed here through Babelfish to translate to English.
http://www.xs4all.nl/~buddendo/aquarium/berekeningen-redfield.htm

Double checked my tank(s) nitrate and phosphate readings converted to nitrogen and phosphorus - still makes no difference. There is no sign of BGA where RF ratio as per conversion indicates there should be.


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## ER9 (Aug 2, 2008)

homer...i think i read that there has to be cotamination of the bacteria for an outbreak to occur under conditions that are favorable for an outbreak (trigger).


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## Homer_Simpson (May 10, 2007)

ER9 said:


> homer...i think i read that there has to be cotamination of the bacteria for an outbreak to occur under conditions that are favorable for an outbreak (trigger).


I am not sure what you mean, that is not what I am reading with the RF ratio article. It specifically makes reference to ratio of nitrogen/phosphorus ratio at a certain level leading to a BGA outbreak I am not seeing any reference in the article that there has to be contamination by bacteria or other conditions favorable to an outbreak or trigger. However, having said that I do believe that excess dissolved organics resulting from overfeeding and overstocking could lead to conditions favorable to its development. I cannot scientifically prove this 100%. It is just based on observation. I only had it in the one 10 gallon tank that was ovestocked. All my other tanks that have never had it are all "understocked" and I underfeed the fish. And I even dose phosphates(eventhough my tap water is really high in phosphates) and nitrates in those tanks.


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## Wö£fëñxXx (Dec 2, 2003)

> (trigger)


What is Hypoxia? I've had my share of every algae known just like most
all of you.

Over grown tanks with dirty/clogged filters w/poor flow and no 02=BGA
Good tank Hygiene and lots of air has proved effective for me.

None of my tanks have BGA any more, that I can see or smell.

Imagine a leaf falling into a stream. The leaf, which is composed of organic matter, is readily
degraded by a variety of microorganisms inhabiting the stream. Aerobic (oxygen requiring)
bacteria and fungi use oxygen as they break down the components of the leaf into simpler, more
stable end products such as carbon dioxide, water, phosphate and nitrate. As oxygen is
consumed by the organisms, the level of dissolved oxygen in the stream begins to decrease
Water can hold only a limited supply of dissolved oxygen and it comes from only two sources of diffusion
from the atmosphere at the air/water interface, and as a byproduct of photosynthesis.
Photosynthetic organisms, such as plants and algae, produce oxygen when there is a sufficient
light source. During times of insufficient light, these same organisms consume oxygen. These
organisms are responsible for the diurnal (daily) cycle of dissolved oxygen levels in lakes and
streams.
If elevated levels of BOD lower the concentration of dissolved oxygen in a water body, there is a
potential for profound effects on the water body itself, and the resident aquatic life. When the
dissolved oxygen concentration falls below 5 milligrams per liter (mg/l), species intolerant of low
oxygen levels become stressed. The lower the oxygen concentration, the greater the stress.
Eventually, species sensitive to low dissolved oxygen levels are replaced by species that are
more tolerant of adverse conditions, significantly reducing the diversity of aquatic life in a given
body of water. If dissolved oxygen levels fall below 2 mg/l for more than even a few hours, fish
kills can result. At levels below 1 mg/l, anaerobic bacteria (which live in habitats devoid of
oxygen) replace the aerobic bacteria. As the anaerobic bacteria break down organic matter, foulsmelling
hydrogen sulfide can be produced.


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## ER9 (Aug 2, 2008)

Homer_Simpson said:


> I am not sure what you mean, that is not what I am reading with the RF ratio article. It specifically makes reference to ratio of nitrogen/phosphorus ratio at a certain level leading to a BGA outbreak I am not seeing any reference in the article that there has to be contamination by bacteria or other conditions favorable to an outbreak or trigger. However, having said that I do believe that excess dissolved organics resulting from overfeeding and overstocking could lead to conditions favorable to its development. I cannot scientifically prove this 100%. It is just based on observation. I only had it in the one 10 gallon tank that was ovestocked. All my other tanks that have never had it are all "understocked" and I underfeed the fish. And I even dose phosphates(eventhough my tap water is really high in phosphates) and nitrates in those tanks.


i know....i cant seem to locate where i read it. i thought it was on tom barrs site somewhere but cant seem to find it....was all over the net reading about this stuff. one of those links led me back to TPT and the chart. i do distinctly remember reading it though. the assumption was that there had to be contamination then favorable conditions for an outbreak.


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## Homer_Simpson (May 10, 2007)

Wö£fëñxXx said:


> What is Hypoxia? I've had my share of every algae known just like most
> all of you.
> 
> Over grown tanks with dirty/clogged filters w/poor flow and no 02=BGA
> ...


This makes a lot of sense. Overstocking and overfeeding of fish, possibly combined with infrequent water changes would also make good hygene difficult so it all ties in. I remember when I kept unplanted tanks, I would purposely incorporate dual filtration and added circulation that often caused ripples in the water's surface. I even did this on a small scale with a small bowl at work where I kept a peppered cory catfish and dwarf aquatic frog for seven years, without any problems, including no Blue Green Algae.


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## Wö£fëñxXx (Dec 2, 2003)

Yes indeed it makes good sense. BGA is nasty stuff, it is not even algae
as you know but an infection. Aquatical Herpes :icon_eek: 

Good tank hygiene and 02...


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## lauraleellbp (Feb 3, 2008)

There definitely has to be a source for the BGA (or any other algae); it doesn't just spring out of a vacuum. 

That being said, algaes are able to spread through all kinds of vectors; especially when introducing new plants.

The Redfield Ratio is much more commonly used and implemented in Europe than here. A chemist friend of mine on TFH's forum has done a pretty extensive writeup; http://forums.tfhmagazine.com/viewtopic.php?f=83&t=24749


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## waterfaller1 (Jul 5, 2006)

Well..my experience with Cyanobacteria in marine tanks{basicly the same thing, right?} has been what you have mentioned~either new tanks with not enough flow, or established bacteria. Or poor husbandry, overfeeding, overstocking, etc.
I am not one who takes dosing _anything_ lightly, I generally go after the cause, not the solution.
But, my experience recently with BGA in one of my fw planted tanks, is in the tank with the least amount of livestock, and the highest flow. My finnex, which has one cpo, and two zebra nerites. It is a 4 gal tank with a 2234 ecco, the flow is kickin' in that tank. I finally got sick of having to wash my hands three times to get the smell off, and got sick of looking at it. So yesterday I removed the cpo and the two snails. I have some old capsules from when I had treated a betta ages ago. They were white, and I am pretty sure something like EM capsules. I cut one open last night, got the powder out, mixed some of it with some water and dumped it in.
The BGA is already gone, 99% of it anyway!


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## Homer_Simpson (May 10, 2007)

For me the best explanation for what may give rise to any type of algae including Blue Green Algae, is the explanation provided by PlantBrain Link #41 in addition to what Wö£fëñxXx posted above.
http://www.plantedtank.net/forums/g...-can-plants-outcompete-algae-nutrients-3.html

Algae spores are present in any tank just waiting for a trigger to multiply. In that sense algae is an ultimate opportunist. And as soon as the conditions are ripe which serve as the trigger, it will materialize. I believe the same is true for Blue Green Algae. Perhaps, PlantBrain will chime in and share his experience. I believe that Blue Green Algae may be caused by a multitude of factors but not the same factors in each and every case. I find it hard to believe that phosphorus and nitrogen can act as a trigger even for Blue Green Algae as I have not seen this in any of my tanks where my tanks met the criteria for BGA as per RF ratio. As stated, Tom Barr/PlantBrain himself has managed repeated times to induce Blue Green Algae by letting nitrates bottom out. More impressive, he has learned to succesfully send BGA into remission after inducing it.


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## Wö£fëñxXx (Dec 2, 2003)

I hate putting anything in my tank that is not plant focused.
Maracyn being one of them, but it is best to kill BGA as fast as
possible.

There is a big difference in flow vs aeration.
Aeration does help, just as important as calm surface and good
C02 during "plant grow mode" it is just as important in reverse.
Good surface agitation/aeration, lots of 02 @ night.

Surface splash is much better than a simple air stone.



waterfaller1 said:


> Well..my experience with Cyanobacteria in marine tanks{basicly the same thing, right?} has been what you have mentioned~either new tanks with not enough flow, or established bacteria. Or poor husbandry, overfeeding, overstocking, etc.
> I am not one who takes dosing _anything_ lightly, I generally go after the cause, not the solution.
> But, my experience recently with BGA in one of my fw planted tanks, is in the tank with the least amount of livestock, and the highest flow. My finnex, which has one cpo, and two zebra nerites. It is a 4 gal tank with a 2234 ecco, the flow is kickin' in that tank. I finally got sick of having to wash my hands three times to get the smell off, and got sick of looking at it. So yesterday I removed the cpo and the two snails. I have some old capsules from when I had treated a betta ages ago. They were white, and I am pretty sure something like EM capsules. I cut one open last night, got the powder out, mixed some of it with some water and dumped it in.
> The BGA is already gone, 99% of it anyway!


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## Wö£fëñxXx (Dec 2, 2003)

waterfaller1 said:


> smell


Just so you know, I don't like posting just below you, I am afraid the
bird will poop on my Moto Grosso. Homer on the other hand looks as
though he may be ready for a shower anyway...

Hehe


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## Hoppy (Dec 24, 2005)

Wö£fëñxXx said:


> Just so you know, I don't like posting just below you, I am afraid the
> bird will poop on my Moto Grosso. Homer on the other hand looks as
> though he may be ready for a shower anyway...
> 
> Hehe


:hihi::hihi:


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## waterfaller1 (Jul 5, 2006)

Wö£fëñxXx said:


> Just so you know, I don't like posting just below you, I am afraid the
> bird will poop on my Moto Grosso. Homer on the other hand looks as
> though he may be ready for a shower anyway...
> 
> Hehe


 LOL.. Would you prefer a beautiful blonde? 















That would only prove once again, that all poop is not equal.:red_mouth


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