# blue green algae and nitrates .. confused



## Lissette (Apr 2, 2005)

Could it be that your test kit is wrong? They have been known to be inaccurate. 

Test kits hardly ever tell you the exact reading. Only a roundabout figure that you can work on. 

Lissette


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## JenThePlantGeek (Mar 27, 2006)

Read up more on blue green algea and the Nitrate to Phosphate ratio. I'm trying to find the link for you... but it basically has to do with having too much of one compaired to the other. Get both in the "ideal" zone, be patient, and BGA will disappear.


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## haydns (Mar 2, 2006)

Thanks for the pointer. Found the following link which talks about Nitrate to Phosphate ratio (Redfield) and its effect on algae.

http://www.xs4all.nl/~buddendo/aquarium/redfield_eng.htm

Will be seeking to maintain the proper ratio.


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## JenThePlantGeek (Mar 27, 2006)

Oooh, that's the link I was thinking of! Hope it is helpful


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## banderbe (Oct 10, 2005)

haydns said:


> Thanks for the pointer. Found the following link which talks about Nitrate to Phosphate ratio (Redfield) and its effect on algae.
> 
> http://www.xs4all.nl/~buddendo/aquarium/redfield_eng.htm
> 
> Will be seeking to maintain the proper ratio.


Just an FYI, Tom Barr (plantbrain) thinks the Redfield ratio is a myth. He's probably got very good reasons for thinking so.

http://www.barrreport.com/forums/showthread.php?t=424&highlight=redfield



> Hello,
> For some time I subscribed to the belief that a 10:1 ratio of NO3O4 was necessary but as I have monitored my nutrient levels during my attempt at EI dosing I've seen this ratio fall or rise far outside this value as I've monitored. I realize idea is to NOT have to test due to poor accuracy but I do anyway just as a monitor and to try to understand the numbers (perhaps the kits are all a placebo).
> 
> In any case I've never understood the reason for the ratio, it seemed more dogmatic than anything and I'm not sure that I can see where NOT maintaining this ratio has been harmful. There may be other factors obsuring an observation however so I wonder if anyone could clarify the reasons and origin of this ratio and the possible effects of falling outside this boundary. Are there other ratios such as micros that can be ignored or that must be maintained for optimum growth? There seems more to be an effect at threshold levels of individual nutrients rather than at ratios.
> ...


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## plantbrain (Dec 15, 2003)

haydns said:


> Thanks for the pointer. Found the following link which talks about Nitrate to Phosphate ratio (Redfield) and its effect on algae.
> 
> http://www.xs4all.nl/~buddendo/aquarium/redfield_eng.htm
> 
> Will be seeking to maintain the proper ratio.


This is patently incorrect,
It has nothing to do with ratio, never did.

It had to do with adding enough nutrients NO3/PO4, I can have all sorts of "ratios" and never get algae, nor induce it.

If I reduce the NO3 down low and keep it there, that will induce BGA.

You can repeat this for any number of PO4 levels, the ratio itself is meaningless since we have the ability to dose and add nutrients.

Not adding enough nutrients is the issue(specifically NO3), not a ratio.

The paper they cite also does not support the web site's contention, nor does the basic premise/hypothesis.
You can do this your self by maniputlating PO4 and NO3 and see.

Something I did a long time ago rather than this anecdotal account of a couple of BGA outbreaks that shows no causation, merely correlation.

And that's how a myth gets started in this hobby.................

Regards, 
Tom Barr


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## h20 plant (Dec 21, 2005)

So what would be different ways to get the NO3 to the right levels and keep it there?


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## Ryzilla (Oct 29, 2005)

I recentley did a test by lowering my NO3 to try and starve that wooly green algae and in return I got a small BGA outbreak only on the crown of my stem plants. I have recentley increased the NO3 up again since I could not kill the wool like algae and the BGA ceased


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## JenThePlantGeek (Mar 27, 2006)

You know, I did the same thing. I had problems with BGA, found the "Redfield Ratio", dosed nitrates, and the problem was solved. I guess that correlation does not equal causation. I will no longer be passing along this myth. Thanks guys. 

Potassium nitrate (KNO3) is used for dosing nitrate. Here's a good place to buy it: http://www.gregwatson.com/DryAquaticFertilizers.asp


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## plantbrain (Dec 15, 2003)

It's not the ratio that saved you, it was adding enough of the limiting nutrient, NO3 for the plants.
That's all it was, and that's even simpler than the RR to tell other folks and you can repeat it fairly easily.....

Regards, 
Tom Barr


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## Osteomata (Jan 6, 2005)

Tom, 
It sounds like we have a defacto ratio given that you need to keep NO3 higher than you need to keep Phospates for plant growth. 10:1 may be an arbatrary number, but the idea of keeping Nitrates up while phospates are moderately present still seems valid, if I read you correct...
Jack


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## plantbrain (Dec 15, 2003)

Well, it's not a ratio dependent, nothing wrong with using it as a guide to limit PO4 or KNO3 waste in a fert routine, but it's sure as heck not why BGA grew or any of those other algae that link claims.

And the levels of PO4 are too low from the article.
I think the author does not realize that RR are atomic ratios, atoms, not molar ratios.

16 N at 14g/mol = 224 
1 P at 30.97 = 30.97

224/30.97= 7.2

So at a mass ratio, 7:1 N

Convert to NO3/PO4 10:1 or so.

If you look at macrophytes' ratios(say 30+ species), you find a ratio of 5:1 to 7:1, or about 7:1 to 10:1.

N:K ratios are fairly equal.

But simply because that is what we find in nature, does not imply in anyway that it is optimal for horticulture.

Farming, fertilizing in agriculture is not defined based on natural plant conditrions, we highly amplify things.

Our tanks are no different.
Since nothing is allowed to become limiting in our tanks, the ratio is not ecologically an issue for the crops, it will save you more money and you will use less ferts if you apply such ratios at large scales, but in our small tanks with cheap ferts? No, you simply forgot to add ferts, that's why you have algae, and adding excess amounts allows you much more wiggle room in a routine.

Regards, 
Tom Barr

www.BarrReport.com


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## Osteomata (Jan 6, 2005)

Tom,
I understand you, and it makes sense to me to a point. But what I am unclear on is: why? Specifically: 

1) If you have a nutrient deficiency, then plants may grow and algae usually grows, with type of algae dependent on the specific nature of the deficiency.
2) If you have optimal plant growth nutrient conditions, then plants grow but algae does not.
3) If you have optimal plant growth nutrients, but no plants in the tank, then algae grows. (I think)?

So what is it about situation 2 that prevents the algae from growing along with the plants? Why don't you have BOTH plants and algae present?

Is it some form of allelopathy (chem warfare)? That is, when plants are given optimal conditions, the plants are producing a natural algaecide/algae inhibitor? I have always heard situation 2 described as "the plants outcompete the algae for nutrients," but if the nutrients are constantly kept available, then it seems like they would be available to both plants and algae.

Or do I simply have situation 3 wrong: Plant growth nutrient conditions are not good for ANY of the wide variety of algae species.


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## JenThePlantGeek (Mar 27, 2006)

I have heard that hornwort indeed makes a chemical that inhibits algae growth, but I have not tested or seen a scientific study on that.


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## plantbrain (Dec 15, 2003)

Osteomata said:


> 1) If you have a nutrient deficiency, then plants may grow and algae usually grows, with type of algae dependent on the specific nature of the deficiency.


Is this a question?
Plants may either just sit and stop growing, this is typical, they seldom just die, this makes them a good place for algae to grow.
But algae are geared to respiond to either increases and or dec reases in nutrient concentrations in their environment.

They are far more senstive to these changes than plants ever could be. 
They also have much more evolutionary pressure to do so. 




> 2) If you have optimal plant growth nutrient conditions, then plants grow but algae does not.


Well, the algae adults can grow in some cases, the spores will no longer germinate and after 2-3 weeks, the adults die off etc.
But as far as the plants, yes.



> 3) If you have optimal plant growth nutrients, but no plants in the tank, then algae grows. (I think)?


Yes.
You have nothing to remove the NH4 other than bacteria break down/oxidation. You have less O2 as well. 
Algae typically can sense when someone else is there.
Mainly through NH4 concentration or reduced CO2 levels.




> So what is it about situation 2 that prevents the algae from growing along with the plants? Why don't you have BOTH plants and algae present?


Simple, algae are better adapted to lower levels of nutrients than the much larger plants, you need a more stable environment for the plants.

When we monkey with changes and assumptions, we screw things up, when we maintain good optimal stable levels for the plants, we no logner get algae.

Why grow if someone esle is already there and removing the NH4?

Algae gprefer CO2 as much as plants, but the plants need much more carbon than the algae do relative to their size and biomass.

So a nicer question, since CO2 is also a nutrient, why does adding CO2 no induce algae also?

Think about that for awhile.
It's pretty simple if you think through it.

[quote
Is it some form of allelopathy (chem warfare)? That is, when plants are given optimal conditions, the plants are producing a natural algaecide/algae inhibitor?[/quote]

No, what are the odds that all 300+ species all illict the same chemical and at the same intensity? There's nothing in the research that has ever shown this to be the case in a lake or a stream.......ever.
Not that is might be there, but it's never been shown.
The ref's cited by hobbyists are very poor refs for applying to living conditions that are similar to our tanks. 
There's also little need. 



> I have always heard situation 2 described as "the plants outcompete the algae for nutrients," but if the nutrients are constantly kept available, then it seems like they would be available to both plants and algae.


Yes.

How are they competiting if they are not in the same niche?
This is like suggesting mice and elephants are strong competitors since both are herbivores. Algae are at such a tiny scale that the ecological differences are radically different.

One cell vs 200 billion cells.




> Or do I simply have situation 3 wrong: Plant growth nutrient conditions are not good for ANY of the wide variety of algae species.


Well the algae just wait till they have a chemical/light etc response to grow.
Plants will grow well if they have enough nutrients.

Take you question further, why do we have more than one type of Algae then? Shouldn't all algae be the same species in our tanks?

Now ask why that might be.

Regards, 
Tom Barr


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## shuks (Jul 10, 2005)

> I have heard that hornwort indeed makes a chemical that inhibits algae growth, but I have not tested or seen a scientific study on that.


I read that too.. I think its a bunch of baloney.


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## JenThePlantGeek (Mar 27, 2006)

Shuks, most likely. Hornwort is such a fast grower that I'm sure it's more along the lines of what Tom Barr said - that the plant (hornwort) outcompetes the algae. Hornwort is one heck of a competitor after all.


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## Osteomata (Jan 6, 2005)

plantbrain said:


> Take you question further, why do we have more than one type of Algae then? Shouldn't all algae be the same species in our tanks?
> 
> Now ask why that might be.
> 
> ...


That doesn't surprise me at all. Different species of algae evolved based upon different environmental pressures. Natural selection, genetic drift, and mutation all had an impact. Evolution occurs as a branching off process, usually with some form of geographic isolation. Its easy to imagine that with a million isolated bodies of fresh water, all containing different levels of macro and micro nutrients, a wide variety of algae species would develop.


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## plantbrain (Dec 15, 2003)

shuks said:


> I read that too.. I think its a bunch of baloney.


No, it's true but very subtle in an aquarium set up.
If you grind up the extracts and add very concentrated amounts on algal cultures, then most things will kill or inhibit algae growth, that's how most of the test have been done to determine things.

This does not mean they work in situ.
We'd see quite different patterns otherwise and adding activated carbon can and is used to add as a control to remove all allelopathic chemical.

So adding AC would cause bloom if you assunme that aalelopathy is the only thing holding back the algae, also, a large water change, say 90% should do the same thing also, but we do not see algae blooms after water changes, quitre the opposite.


Regards, 
Tom Barr


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## plantbrain (Dec 15, 2003)

Osteomata said:


> That doesn't surprise me at all. Different species of algae evolved based upon different environmental pressures. Natural selection, genetic drift, and mutation all had an impact. Evolution occurs as a branching off process, usually with some form of geographic isolation. Its easy to imagine that with a million isolated bodies of fresh water, all containing different levels of macro and micro nutrients, a wide variety of algae species would develop.


And a wide array of niches that plants occupy as well
Do you think that both niches are the same for the algae and the plants?

No.

Regards, 
Tom Barr


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## Alight (Dec 10, 2005)

OK, I think I've got it and also may have no hope of controlling the hair/thread algae in my tank. 

The problem is, I'm overstocked with Discus--pigs that they are. With gravel in the tank, there will always be an overabundance of NH3 being produced, no matter how fast the plants are sucking it up. They just make too much. Even though I'll never see the ammonia, because I have a great biofilter. Ammonia is still being made at a rapid rate. So all my efforts to increase CO2, adequate ferts, lighting, have just added fuel to the fire, so to speak. No matter what I do, the algae always has excess ammonia to feed on. The only solution is to remove some of the fish. 

I suppose if I could get plant growth to the state that I actually had to add nitrates, as opposed to removing them every 3-4 days, I might eventually win--but I'm not that close, yet.

I'll still go down kicking and screaming as I keep trying to get the right fert balance and keep upping the CO2 until my fish scream (and I do, too), and twice a day scrape out all of the algae my little fists can remove from the plants.


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## mrbelvedere (Nov 15, 2005)

Maybe get rid of a few discus?


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## shuks (Jul 10, 2005)

> Originally Posted by shuks
> I read that too.. I think its a bunch of baloney.
> 
> 
> > No, it's true but very subtle in an aquarium set up.


Wow! I learn something new every day.


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## Alight (Dec 10, 2005)

_Maybe get rid of a few discus?
_

)LOL) That was my original plan when I first set up the tank. But now I have two breeding pairs, and my wife loves all the others, so we can't part with them. I now have two other tanks full of Discus, and sell some every month, so I'd actually like to put MORE in the tank, but it ain't gonna happen. 

Sigh! the best laid plans....

Back to the algae pulling.


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## plantbrain (Dec 15, 2003)

Alight said:


> OK, I think I've got it and also may have no hope of controlling the hair/thread algae in my tank.
> 
> The problem is, I'm overstocked with Discus--pigs that they are. With gravel in the tank, there will always be an overabundance of NH3 being produced, no matter how fast the plants are sucking it up. They just make too much. Even though I'll never see the ammonia, because I have a great biofilter. Ammonia is still being made at a rapid rate. So all my efforts to increase CO2, adequate ferts, lighting, have just added fuel to the fire, so to speak. No matter what I do, the algae always has excess ammonia to feed on. The only solution is to remove some of the fish.
> 
> ...



Given the species of algae, it was more likely due to low nutrients and poor CO2 at some point.

Now it's there, it'll be harder to weed out.
You can also switch food, or feed less.

Check other thread/hair algae threads.

I have stocking densities up to 1 adult per 10 gal on a 120 gal sized tank, I prefer about 5-6 fish in a 90 tall though.


This is a nice number and gives them enough room to live thier entire lives.

I never add fish to a tank they cannot live out their entire lives at a full grown size. Get a bigger tank, or reduce the fish load or switch the fish type, food etc.

Automatic water changers are fairly popular here for the Discus folks in the SF Bay area.

Regards, 
Tom Barr


Regards, 
Tom Barr


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## arisk (Jan 11, 2004)

Osteomata said:


> 2) If you have optimal plant growth nutrient conditions, then plants grow but algae does not.
> 
> So what is it about situation 2 that prevents the algae from growing along with the plants? Why don't you have BOTH plants and algae present?


Nice to see this question asked, as it is certainly a concept I have struggled with as well.
I'm not in a position to argue with results or experience. Obviously it works, but I still don't know why.
I've rationalized it by the assuming great plant growth keeps NH4 low and algae growth is not triggered, but that could be totally incorrect.

After reading Tom's reply further down, I'm still confused.
Do new spores not germinate due to too low NH4?
Why don't adults continue to grow(and better than before)? What process reduces the amount of algae?


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## Alight (Dec 10, 2005)

Thanks for the response, Tom. I'm close with 6 Discus in the 55 to the one per 10 gallon thing. From time to time, I have as many as 8 in the tank, though as my breeders cycle through tanks. 

Overall, nitrates go up about 2-3 ppm per day. They go up faster after a trim/thinning, and slower with no trim. Phosphates start at undectectable levels and go up to less than 1 before a water change if I don't add them. I put K at 20 after a water change, and it doesn't seem to change much. I dose micros after a water change, and every other day after a change. I dose iron every day, as the Macranda tells me it needs that to be bright red.

Calcium and Magnesium are about 75 and 35 ppm respectively. CO2 is about 30-35 ppm--but only that for the last few days.

After the last water change (two days ago) I tried upping the PO4 to 1.5 immediatly after the water change. The nitrates the next day were 5 ppm, but the algae seemed to grow even faster than before.

It may be that I fed more Hikari Discus food which seems to be much higher in phosphates and nitrates as the end product, than the usual meal of FBW or Tetra Color Bits. I'll experiment with that a bit to see if it was the food, or the phosphates that caused the addition growth.

I'll keep reporting on this until I get it right. I'll probably do the main report at SimplyDiscus.com in the Planted Tank Section, as I sort of highjacked this thread at this point.

Al Light


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## plantbrain (Dec 15, 2003)

By my and several other folk's estimations, the 120 had about 50% of the demand of N coming from fish. We still had to add 1/2 teaspoon KNO3 2-3x a week.

Your tank would normally need 1/4 teaspoon 2-3x to maintain the NO3.
You might consider less fish, less swapping of fish in/out etc.
Larger water changes etc.

Well run and packed full of plants, the tank should decline at this stocking level.

But the farther away you are from low NH4 production, the less wiggle room you have and the greater potential for algae.

I personally will not add discus to anything less than 80-90 gal tank and Discus folks for all their zealotry, just don't get that part. I had 5 Blues in a 90 and the tank was packed with plants(I added 3/4 teaspoon 3x a week KNO3). I would not try and keep 5-6 Jack dempsy adults in a 55, nor would I do the same with these big cichlids either.

It looks bad too, it's overcrowded with big fish in a small tank, that is very unasethetic. Maybe as well go bare bottom if you cram that many fish is a small tank.

I just don't like the trade offs here, and the algae issue is just part of it.
I'll tell you what you can do, but realistically, there is one very simple ethical solution and it's something that will make the care for the tank much easier.

I'm not lecturing you here, I'm just pointing out some trade offs you must address, *you cannot have both *unless you plan on very frequent large water changes, eg, every other day or 50-60% 2x a week etc.

That's the only way we kept that many fish in the 120 and had the plants do well.

Regards, '
Tom Barr


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## plantbrain (Dec 15, 2003)

arisk said:


> I've rationalized it by the assuming great plant growth keeps NH4 low and algae growth is not triggered, but that could be totally incorrect.


With soem algae, this is true. GW for example is a good one.
Staghorn is another.
Perhaps others like _Oedogonium_.



> After reading Tom's reply further down, I'm still confused.
> Do new spores not germinate due to too low NH4?
> Why don't adults continue to grow(and better than before)? What process reduces the amount of algae?


New spores, and old spores, any spore will not germinate unlessd there is a critical concentration of NH4 present. I do not know how much that amount is really, I wish I did and will find a decent way to figure and estimate this later. It's much tricky than it might seem. N is used up so fast it's difficult to measure, it's basically used up as fast as it's produced. But as the loading rate increases, the levels slowly increase. The other possible issues with fish loading, the discrete packs of highly concentrated fish waste can have a much higher level of NH4, or like when you pull up a Jobes stick.

You might not measure much in the water column, but there's a lot down on the gravel where spores settle and wait. 

The other main issue is the timing of the measurements, how long till you see a response and did you add a known amount of ppm NH4 and then measured the decline.

Also, who gets what?
How much of the NH4 is taken in by plants?
How much is taken in by the algae?
How much is converted to NO2=>NO3 by bacteria?

This is not a simple issue.

You can add say .5ppm of NH4 from ammonium sulfate or chloride and get GW.

You can toss in a jobes stick to a high light 20 gal= > GW in 1-2 days.

The adults grow for awhile, then produce spores, then they die.
If conditions are ripe for continued growth, some species hang around.

When you do water changes, scrub etc, this causes the adult algae to sporulate, they, the adult parental algae generally die soon afterwards.

Much like annual plants when the winter comes.
The next season's/year's seed germinate when conditions are good for them.
They do not germinate right away.

Most spores also germinate over time, some are fast to respond, some are slower, this gives them the best chance at survival, as long as few are around, even if they are lost most of the time, when the changes in the environment are much greater than normal, these slow pokes or fast responders will have an advantage.

Think about it like weeds in your garden.
They have their seasons also.

The spores are awlays there.
We make them germinate by not focusing on plant growth.


Regards, 
Tom Barr


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## unirdna (Jan 22, 2004)

Osteomata said:


> So what is it about situation 2 that prevents the algae from growing along with the plants? Why don't you have BOTH plants and algae present?


I agreed with everything Tom had to say....up until he answered this question.

Osteomata,
IMO, You have now caught up to all of the experts in this hobby. The great question of what prevents algae growth in the presence of a plethora of nutrients. Tom will contest that NH4 is the single cause for all algae outbreaks. I remain skeptical of such a simplified hypothesis. I have my own evidence that suggests that while dying plants support algae outbreaks, NH4 (from heavy fish loads) does not. Something is missing.....but, that is a subject for a different thread.


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## Alight (Dec 10, 2005)

Tom, you are correct in your suggestion for the best fixes for the problem. Either fewer fish or larger tank. It was my original intention, but I'm stuck a bit. While I'd love to have a bigger aquarium for my show tank, space considerations and aesthetic in the room make it impossible for me to convince my wife that we should have one.

I already do 60% water changes whenever the nitrates are over 10 ppm, which is every 3-4 days. Without the plants, it would be every other day. 

I may try to increase water changes with 5 ppm as the target and see what happens, if the PO4 addition I'm doing now doesn't cut down the algae growth. It seemed to speed it up, initially, but I always give changes at least a week to see what happens in the long run.

It's every day, 60% in my bare bottom grow out tank!

I have a really nice batch of Juvies from one of my spawns that would look great in the Show Tank. Maybe when they pair up, I can get up the nerve to keep just two pairs, and sell the rest of the stock. 

BTW, the plants grow great in the show tank, in spite of the algae problems. Beautiful Macranda (which seems not to collect algae), swords, Magenta, crypts, cabomba (also keeps algae at bay), Difformis, Corumbosa, Red Temple. I give away lots of trimmings every week. The trimming is almost as much a problem as the algae pulling. 

I really see the difference in having to add nitrates vs nitrates from the fish as the rate of NH3 production. When adding nitrates, NH4 production is low. The othe way around, it's high. I may not actually be the amount of NH4 that is necessary to wake up algae. It may be the _rate_. Differential equations instead of linear ones. 

I know that the rate of NH4 can stimulate biofilter bacteria growth. It doesn't actually take the presence of any measurable ammonia. So why not the same for algae?

Unirdna, I really hope you're right--that NH4 from fish does not necessarily support algae growth. I don't have rotting plants in my tank. I do alot of maintenance twice a day when I pull the algae at each feeding. Any suggestions for what I might try?


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## unirdna (Jan 22, 2004)

I have a 50g planted tank system with 100, quarter size angelfish in it (breeding station). The nitrates stay way ahead of the plant uptake, and there is measureable NH4 moments after each feeding (twice a day). Still the tank has no algae. It has been this way for over a year. I do water changes to remove excess nitrate. 

Yet, in this same system, I have occasionally introduced a plant that didn't do well. In this case, when the plant started to die, it became engulfed with hair and staghorn algae. All the while, the surrounding [healthy] plants didn't have a spec on them. Observations like this leave me sceptical re: the NH4 = Algae hypothesis.


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## Alight (Dec 10, 2005)

Very interesting. What is the nitrate level in the tank? I've noticed that algae growth decreases at very high nitrate levels (60 ppm or more).

So get this, I noticed last night (noticed it before, but it didn't sink in until this morning) the the hair/thread algae seemed grow very fast _overnight!!_. How could algae grow without light? 
Then, it hit me--when the lights are off, the plants very quickly quit pearling--pearling being the sign they are very rapidly using nutrients. So, the rate of nutrient increase must be rising very quickly when the lights are off. 

I've also noticed that the hair/thread algae doesn't bother the most rapidly growing plants in my tank, or the substrate.

Maybe the "rate" idea I suggested above is more encompassing than I thought.

Maybe it's the rate of NH4-nitrate-phosphate production vs. reduction, that is the key, and the absolute level of these nutrients has very little to do with it. 

It could very well be that algae is programed to grow faster and activate spores when the above nutrients are rising rapidly. When they rise slowly or actually decrease, algae growth slows, stops and spores quit germinating. 

Providing adequate ferts allows plants to grow quickly, causing a negative rate of increase when there are enough plants relative to the nutrient production rate. 

At a micro level, a dead plant is a net source of nutrients, so production increases on these plants. Slowly growing plants also take in less, so the rate of reduction near these plants is low. Near rapidly growing plants, the rate of reduction is high, so algae doesn't like the environment. 

Sort of takes the "outcompete algae" hypothesis and combines it with adequate fertilization, nicely. 

It could still be that it is the combination of nutrient increases/decreases, not any one nutrient that signals these changes. The combination may be slightly different for different forms of algae. 

Since NH4 is an intermediate step in the production of nitrates, it would explain why it seems to be important, but doesn't always fit the equation. 

This could all be tested in the laboratory, or if someone has a bunch of 10 gallon tanks and test kits (I don't).


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## Osteomata (Jan 6, 2005)

Question regarding "Nitrate equivalent":

Based upon this thread I have been trying to adjust my water parameters (by increasing Nitrates) to defeat my current BGA problem, and I am making progress. My test kit still reads less than 5ppm Nitrate, while my Phosphate level is about 1.5ppm. So I have been trying to raise my nitrates by increasing my dosage of Flourish Nitrogen. 

My confusion comes from the instructions on the back of the bottle: the formula for increasing Nitrogen increase is .25vn = m where v is the volume of the tank, n is the desired nitrogen increase, and m is the amount in ml of Fl N to add. When I run this forumula for a 5ppm Nitrogen increase in my 15G tank, I get about 19ml. Thats a lot! The "beginner" directions on the bottle recommend only 1.25ml twice per week for my size tank! Now, it does say that if I am using "nitrate equivalent" value for "n" then I should only use a constant of .05 instead of .25. The result seems much more reasonable (3.75ml of Fl N added)

So what gives? Am I supposed to be using a Nitrate equivalent? SO far I have only added about 7 ml total over the last week.


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## plantbrain (Dec 15, 2003)

unirdna said:


> Tom will contest that NH4 is the single cause for all algae outbreaks.


No, I have never said that this is the *only thing*.
You want to mistinterpt my words and assume. 



> I remain skeptical of such a simplified hypothesis. I have my own evidence that suggests that while dying plants support algae outbreaks, NH4 (from heavy fish loads) does not. Something is missing.....but, that is a subject for a different thread.


I also include stable CO2 levels(low or high). 
BBA, GSA and perhaps a few others fall into this group.
Hair algae tends to fall into the limitation of plants.

It's not all encompassing, but just a general notion, but there are other things such as low NO3 for the plants and BGA, BBa and CO2(both in non CO2 and CO2 enriched tanks etc)

What happens when dying plants decompose?
They are broken down into what precisely?
Inorganic nutrients.
Which are?
NH4 before they are NO3.........
Add some jobes sticks to the water column, they contain the same things.

You need to keep adding more fish if you think heavy fish loads will not induce algae Otherwise if you accepted your own hypothesis......shouldn't we simply add more fish and some K2SO4 instead of KNO3 in a higher light/CO2 tank?

In a non CO2 tank the rate of NH4 from fish waste alone is enough to support the much slower growth rates of the plants.

I've done that, you need to go farther is all.
You also need to dose NH4 inorganic forms and see what happens as well as add a few more fish progressively and wait aboput 30 hours in between the additions of more fish/shrimp etc.

You have done little so far.
You have discovered that doing a big hack/pruning and then no follow up water change = GW. Welcome to the club, Neil Frank and I knew that 15 years ago. That can be traced to NH4.

Folks played around with adding NH4 years ago, that led to GW blooms and staghorn algae. See APD, our club members did this about 7-8 years ago and played around with a few things with NH4+. Everyone abandoned it as NH4 is playing with fire. 

As stated in the other thread....
These are test you can do and try, but you have not finished nor are able to conclude much so far.

Try the jobes, try adding progressively more fish till you get algae, try dosing NH4+ inorganically.

There is a way to dose NH4 and not get algae, but it's very impractical.

Regards, 
Tom Barr


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