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What is the relationship between nitrate and algae

68K views 57 replies 12 participants last post by  steelerfan 
#1 ·
just curious what role does nitrate play with algae? in a tank with 0 nitrate can algae form? lets assume this is a non planted tank.
 
#2 ·
Nitrate is a chemical compound of one part nitrogen and three parts oxygen, hence the symbol NO3. It is a naturally occurring ion, a product of the oxidation of nitrogen by micro-organisms in plants, soil and water. In the aquarium, bacteria produce nitrate from nitrite, which itself comes from ammonia and ammonium. Nitrate is thus a form of nitrogen.

Algae is a plant, and all plants need nitrogen as one nutrient. As I explained in two prior threads, plants have the ability to use all three forms of nitrogen normally available in an aquarium: ammonia/ammonium, nitrite and nitrate; but most prefer to use the free ammonia or ammonium. Algae and plants need more than just nitrogen, they also need CO2, macro-nutrients and micro-nutrients, and all this in the presence of light.

Algae generally occurs from an excess of organic materials and poor water quality, or an excess of nutrients. In the absence of higher plants, these nutrients are readily available since they enter the aquarium through fish food and water. An excess of soluble iron can also cause a bloom of single-celled or filamentous "green" algae. Another reason to avoid dosing individual iron unless it is in balance with all 17 nutrients that plants require.

It is therefore possible to have nitrates without having algae, if the other nutrients required for algae/plants are not present. Similarly, algae can be present without nitrate since the algae does not need nitrate in order to obtain its nitrogen. Without nutrients, there can be no algae.

In aquaria with problem algae, the nitrates are usually high. Nutrients that feed the algae also contribute to the nitrogen cycle, along with the fish and other bacteria. Excessive levels are bound to impact several processes ongoing in the aquarium.

Byron.
 
#4 ·
It is therefore possible to have nitrates without having algae, if the other nutrients required for algae/plants are not present. Similarly, algae can be present without nitrate since the algae does not need nitrate in order to obtain its nitrogen. Without nutrients, there can be no algae.
please clarify this the above in bold?
surely the last thing you would want is any nutrient at all to be lacking, is this not one of the things that actually causes algae?
isnt it a much better idea to make sure the plants have everything they need in non limiting supply?
as soon as the plants struggle or stall will they not release more organic waste themselves that will cause algae to trigger?
algae is an opportunist and as you say likes a fluctuating environment. keep the nutrient levels non limiting so the plants grow healthy and youre half way there!

In aquaria with problem algae, the nitrates are usually high. Nutrients that feed the algae also contribute to the nitrogen cycle, along with the fish and other bacteria. Excessive levels are bound to impact several processes ongoing in the aquarium.

Byron.
maybe.
but it'd probably be a far more realistic to say in aquaria with problem algae the lighting is too high for the levels of available CO2, nutrients and/or flow

as you say high nitrate are an end product of the nitrogen cycle, would that not mean there has been levels of ammonia first? does it not make more sense that this sign of a possibly un healthy/un stable environment is far more likely to be a cause of algae than the end product of nitrate?
 
#5 ·
The original post in this thread asked about a non-planted tank.

As for the bold statement, nitrate is only a form of nitrogen. Algae can't live with only nitrate, it needs all the other nutrients.

The light itself does not cause algae. Nutrients have to be present in light. Plants are higher forms that can photosynthesize faster than algae, which is why turning the lights out mid-day for an hour or two will not negatively affect the plants but can impact algae which needs longer light duration to compete. And if CO2 is the limiting factor, then light that is beyond the balanced intensity for the CO2 will create an environment for algae because they are better able to obtain carbon from carbonates. Some plants are quite good at this, Vallisneria for example, which is why is grows so well in alkaline water which has a higher carbonate hardness; but others are not and rely far more on CO2 and these are then at a disadvantage in such a situation. Which is why algae frequently appears faster in alkaline water than in acidic, all else being equal.

I previously noted that algae occurs due to high organic materials and poor water quality, as well as from excess nutrients.

BH
 
#6 ·
ah yeah, i missed the non planted bit! :0)

thanks for clarification it seemed you were saying as long as one nutrient was not there then algae wouldn't grow.

but this is interesting none the less.

algae like unstable conditions right?
so how is it that turning the lights off for one or two hours help stop it?

isnt the function a of light siesta to give time for co2 levels to "recharge" therefore keeping the plants healthier?

so would it work to have lighting in two hour sessions with and hour break between each, would this not discourage algae even more than one lighting break?
 
#8 ·
Seems to me algae is a plant or plantlife. Makes since to me that limiting light, or blacking out a tank, would stifle growth. But I ain't no plant person at least in regards to the aquarium.
I can grow orchids and gardenias in the boileroom here at work but my success with plants in the aquaria have been spotty at best.
Let's not forget were talking about non planted tanks now and how or what contributes to alage growth in that regard.
 
#9 ·
I am always willing and eager to learn. Perhaps those who have dismissed the often accepted reasons for algae growth would share their opinions on the primary cause of algae. Not that which contributes to it ,but rather the root cause. I'm all ears, Just ask my mother.
 
#11 ·
Thanks so much . My own extensive searches do indeed list those as contributers but when primary causes are asked for ,all my searches indicate excess nutrients,phosphates, silicates,and dissolved organics/waste. Searches for biologist's views,government studies,etc all seem to incude the same info. Is it possible that the causes are too numerous to excude that which is most often sited? or are all but a few ,,simply ignorant? Could it be that there are as many causes as there are ways to be ignorant?
 
#13 · (Edited)
Thanks so much . My own extensive searches do indeed list those as contributers but when primary causes are asked for ,all my searches indicate excess nutrients,phosphates, silicates,and dissolved organics/waste. Searches for biologist's views,government studies,etc all seem to incude the same info. Is it possible that the causes are too numerous to excude that which is most often sited? or are all but a few ,,simply ignorant? Could it be that there are as many causes as there are ways to be ignorant?
most of these studies are of river systems right?
could they not be a little bit different to the way your tank runs?
could you leave your tank in direct sunlight for 10 hours and not get algae?

back to aquariums.
i understand that ppl get algae and test the tank and find nutrients(phosphate or nitrate) high and immediately conclude that these high levels caused it.

could it have not been just poor tank maintenance?
dirty filter, also having knock on effect of reduced flow?
low oxygen levels?
other nutrients in low limiting levels?
low co2 levels?
too long and high light?

when ppl get algae they usually do a few things and i'm sure most here would advise the following....

frequent large water changes?
general maintenance and filter clean etc? (this would also improve filter effeciency and flow)
lower lighting.? (duration and or intensity)
reduce fish feeding?

all sound good? most ppl would do a few of these to fight the algae?

so, manually remove the algae, do a few large water changes and some of the above and algae has gone, yeah?

"sweet that was because you lowered the nitrates/phosphate etc etc........."

was it?

when ppl do a water change they would usually remove the algae manually plus the waste water would remove many algal spores, 50% W/C would be around 50% of the algal spores removed, i guess?
so a few of these water changes would not "just" lower the nutrient levels

i would do the above in my old low tech and my algae would go.

but wait.......

my tap water has 40pp nitrates and 4ppm phosphates. so was i even lowering the nasty nutrient levels?
maybe a bit, but still high levels for a low tech, yet the algae would go.

how could this be?
maybe it was the other factors that influenced the disappearance of algae more?
because it wasn't taking the nasties to low levels that alleviated the problem.


my current tank has high light and high levels of ALL nutrients,
but if i was to let the tank maintenance go a bit,
no filter clean for few months,
no water change for a week,
no water top ups so co2 levels drop (due to increased surface agitation),
no fertilization.
obstructing water flow with unmaintained plants,
removing dead leaves etc.

then i would more than likely get algae,

if i keep up on the above then i dont get algae.

nutrient levels (nitrates phosphates etc) would likely be very similar in both cases.
so in my tank i can safely say high nutrients are not causing the algae if any has appeared.

to quote byron from another thread.
There are people who believe the earth is flat, notwithstanding scientific evidence to the contrary.
BH
he is totally hitting the nail on the head.

the world is not flat,
and neither does high nutrient (no3 po4) levels CAUSE algae.
 
#12 ·
The absolute bottom line is that algae is a plant, and all aquatic plants require light and nutrients or they cannot and will not live. Period.

And I would challenge anyone to find scientific evidence that the above statement is in error.

All or any of the other things mentioned will only be a contributing factor if the algae has light and nutrients.

There is scientific fact behind this, and what any of us may believe is irrelevant.
 
#19 ·
thank you.
and i'm sorry if i've come across as bolshy or argumentative, it just bugs me to see the old "myths" still perpetuated.
in this case the one where people blindly quote "nutrients cause algae"

i thought things had changed a little in recent times, with ppl like tom barr and others, along with the amount of testing and research that has been done and shared with the masses through the internet.

it seems every forum has its "beliefs" tho, usually this is just what the "senior" members think.
however, these are not always in line with the current or latest ways of thinking.
doing something because its the way its always been is not necessarily the best approach........
 
#15 ·
Am I the only one right now with a spinning head? :crazy:
This thread contains more info than I can process, at the moment.
I liken this to a text book that I have to read more than once in order to "get it".
I'm sticking with a theory my mom always used to say, "Ignorance is bliss". LOL
 
#21 ·
Let me just say this.......I have been raising fish for over 20 years and your so called "old myths" have worked for that long for me.........I have over 13 tanks in my house and very minimal algae in any tank of mine, so obviously to me the old myths DO actually work and adding all the extra nutrients into you water is uneeded and a waste of money....My tanks are a mixture of heavily planted tanks to no plants at all and as i stated, algae is at minimum......Trying to beat people over the head with your methods is not the way to approach people here, remember everything that you read now is going to be outdated at sometime in the future.....Are YOU gonna change your ways when that time comes?..........Are you going to take the so called cutting edge "NEW" advice?........I doubt it, your to passionate about your ways to change and see any other facts that have been presented here......How is it that ALL the people here are wrong and you and your newly recruited friends are the only ones who know everything about algae?.........Recruiting members from your local area to back yourself up here is not doing this forum any good and your creating a hostile atmosphere with pointing out ALL the mistakes you think that we are all doing in our tanks...........There are some very knowledgable people here and belittling them because theyre ways and thinking dont jive with yours is just rude and wrong, no matter what side of the Big Pond your from.....You talk about learning new things, how about you learning new things and try to treat people with some respect, even if your opinion differs from theirs
 
#23 ·
Let me just say this.......I have been raising fish for over 20 years and your so called "old myths" have worked for that long for me.........I have over 13 tanks in my house and very minimal algae in any tank of mine, so obviously to me the old myths DO actually work and adding all the extra nutrients into you water is uneeded and a waste of money,....My tanks are a mixture of heavily planted tanks to no plants at all and as i stated, algae is at minimum......
Heavily planted or not, your aquarium water may contain all appropriate nutrients needed by your plants for the amount of light you have. Secondly what is with the 5 point ellipses?

Trying to beat people over the head with your methods is not the way to approach people here, remember everything that you read now is going to be outdated at sometime in the future.....Are YOU gonna change your ways when that time comes?
Yes if there is enough evidence to support the theory, Take einsteins theory of relativity, nobody can prove him wrong yet so it remains a theory yet people believe in it.

I doubt it, your to passionate about your ways to change and see any other facts that have been presented here......How is it that ALL the people here are wrong and you and your newly recruited friends are the only ones who know everything about algae?
Could that possibly because we have tanks with high nitrate and phosphate levels yet no algae??!! When algae is in a system and nitrates and/or phosphate are present also, people make a false correlation.

Recruiting members from your local area to back yourself up here is not doing this forum any good and your creating a hostile atmosphere with pointing out ALL the mistakes you think that we are all doing in our tanks
Could this also possibly because there is a community of serious hobbyists, that actually try things scientifically, instead of making up points and then linking to papers that have nothing to do with planted aquaria??


There are some very knowledgable people here and belittling them because theyre ways and thinking dont jive with yours is just rude and wrong, no matter what side of the Big Pond your from.....You talk about learning new things, how about you learning new things and try to treat people with some respect, even if your opinion differs from theirs
Yeah, there are some knowledgeable people here, its just that they cant actually back up their claims, and they're not even willing to listen to the points we are making, we are backing up our points with relative information instead of papers about freshwater eco systems and not planted aquaria.
 
#22 · (Edited)
I will ,out of fairness,, visit the site recommended but am presently researching ..Redfield Ratio along with Tom Barr's Non CO2 method. I should perhaps note that my research thus far has not been confined to River systems you mentioned although I have spent a large portion of my life on them from the Potomac, to the Rio Grande. No, my interest lies in the primary causes for algae in aquariums. specifically non planted tanks and or low tech. these tanks hold fish and as such , I have no interest in dosing with fertz ,or chemicals ,or antibiotics.etc.
Again ,I thank you for sharing with a self confessed skeptic.
P.S. I would drink the water from my tanks at any given time of day or week. So, No,, poor tank maint would not be source for algae problem with my particular tanks.
 
#26 ·


Cryptocoryne willisii x lucens
Microsorum pteropus
Anubias nana
Anubias nana petite
Pogosteemon helferi
Valliseneria nana

Ive just done a test on the tank and nitrate is 50ppm and phosphate is 3ppm

Surely a recipe for disaster going by the 'old' theory, then why is there no algae? and with it being a new tank, there is even more scope for algae, yet there isn't any, surely this says something? And when you can find proof that NO3 and PO4 levels that i dose on my tank will affect my fish, then i may believe what you say, but i know for a fact that nitrates are not harmful to fish until you get up to about 400ppm, and science has also proven this!
 
#27 ·


Cryptocoryne willisii x lucens
Microsorum pteropus
Anubias nana
Anubias nana petite
Pogosteemon helferi
Valliseneria nana

Ive just done a test on the tank and nitrate is 50ppm and phosphate is 3ppm

Surely a recipe for disaster going by the 'old' theory, then why is there no algae? and with it being a new tank, there is even more scope for algae, yet there isn't any, surely this says something? And when you can find proof that NO3 and PO4 levels that i dose on my tank will affect my fish, then i may believe what you say, but i know for a fact that nitrates are not harmful to fish until you get up to about 400ppm, and science has also proven this!
Obviously there is no algae in this tank because the plants are utilizing the nutrients, whatever they may be, and speaking for myself I have never said high nutrients cause algae nor have I said phosphate alone. I would think just the opposite. Plants need 17 nutrients to exist and grow, in porportion. Although dosing excess of certain ones may cause problems in time. And I still would not sit idly by with nitrates at 50ppm in my aquaria. I never have nitrates above 5ppm, and algae is not a problem unless I overdose nutrients, which as I mentioned in one of the related threads I did and have now cut back, and algae has responded accordingly.
 
#33 ·
And why would you not have nitrates above 5ppm? it isn't bad for the fish and it doesnt cause algae so why??[/quote]

The nitrates are low because the plants use the nitrogen. It is common in a healthy, thriving planted tank to have very low nitrates. High nitrates in a planted tank is a sign of biological imbalance.

I know i broke my promise not to post further, but this is so blatantly obvious, and speaks volumes to some of us. That's it.
 
#35 ·
i dont dose any plant nutrients, my nitrates are under 20 all the time, and my tanks are heavily planted and doing great..........You didnt disapprove anything, except in your own mind....Why would everyone hear change over to your so-called way of a planted algae free tank, when most of us, dont have an algae issue?.......How is it that you and your few friends are correct and everyone else is wrong?..............Think of it this way...........Whether your car is carburated or fuel injected, they both get you to the same place
 
#39 ·
fantastic post Galvanize.

i beleive there is a fair chance not many here have heard of tom.
just to mention he is not your average aquarist.
this is copied from an on line interview with him.

1. Please tell us a little bit about yourself (your CV).

Education:
Water Treatment: Sacramento State
BS in Aquatic Biology: University of California, Santa Barbara
MS in Botany, University of Florida, Gainesville
Ph.D. in Plant Sciences: in progress, UC Davis

I teach Biology at a Community college. In the future I will seek a position at UC as a professor and researcher.

Planted aquariums have been my focus since 1989. I've had some plants in my tanks since about 1977 and was keeping fully planted tanks before starting my college education. For about 10 years I've maintained, designed and 'scaped planted aquariums as a business. These tanks have ranged from about 1 gallon to almost 1600 gallons.






you may wanna start adding some micros i would think that'd help.
low nutrients will cause the algae type you have in the tank pictured on yer profile.

i for one am not saying to anybody they should run thier tanks like mine.

what i am saying is high nutrient levels don't cause algae. (which i think gavanize has done a little better in the last post then i could tho..............)
if your levels are low then that will be fine too as long as all the required nutrients are present, as soon as one of them is in limitation then problems occur.

i guess all you guys who are trying to test these low levels also use calibrated test kits?
not really very accurate other wise are they?
 
#37 ·
Let me point out a perfect parallel from my side of the hobby. Eric Borneman does not use a protein skimmer on his reef systems. He runs a high-nutrient system and experiences very good coral growth. This does not mean that everyone needs to remove their skimmers! It simply means that this hobby is about NUTRIENT BALANCE. The type of aquarium is irrelevant. Be it live plant or reef system, nutrient input needs to be in balance with nutrient export. If not problems result, such as issues with carbonate buildup or depletion.
 
#38 ·
Here are a few quotes from the papers published by Tom Barr.

Rapid growth tanks:

“Often in aquariums using CO2 enrichment, nitrogen deficiency is common and is often remedied via the addition of potassium nitrate (KNO3) and, to a lesser degree, fish waste as ammonium (NH4) and urea, or as the end product of nitrification (NO3). A lack of nitrogen can greatly slow and harm plant growth, causing algae problems as the plant health deteriorates”.

For slower growth tanks:

“With low light and low CO2, few plants, high fish stocks and over feeding, NO3 levels are in excess, but it is the production rate of NH4 that will generally cause an algae bloom. Today, many planted tank hobbyists have looked more critically at their plants and nutrient levels and focus on the real goals, growing plants and not worrying about algae. When plants grow well, algae does not.

This is also true in natural systems even when the nutrient levels are high (Canfield et al 1983) in shallow semi tropical lakes with macrophytes growing in them. Canfield looked at a large number of lakes and found no correlation between nutrient levels and the presence/absence of macrophytes.

Nutrients locked up in macrophytes were often ignored (as in Philips often cited paper 1979, while the algal components were often added to the sampling. This sampling error in effect, showed plants preferred less nutrients. Once the nutrients in the plants was added, the pattern disappears."

The forms of nitrogen in our tanks:

“The two forms that plants will use are NH4 and NO3. There is a distinction between dissolved organic (DON) and dissolved inorganic (DIN) in the water column. Plants use the DIN fraction, but have trouble with the DON fraction. While there is some scant evidence that plants will use a small amount of NO2, it is a generally toxic anion that plays an insignificant role in our tanks. Try adding NO2 and see if the plants remove any significant amount. Try many species. The concentration levels will sit there, unless there are bacteria to convert it to NO3, which is then removed by plants. Stable isotope 15N studies showed submersed macrophytes tended to prefer NH4 to NO3 as a source of nitrogen (Bowes 2004)."

NOTE: the DIN fraction is also what we dose via KNO3 etc

Dosing KNO3 to add nitrogen:

“Higher nitrogen levels can lead to potassium (K) depletion, so using KNO3 allows us to buffer the K levels.”

NH4 triggers algae blooms:

“Add NH4 to a planted tank with no fish, no filter and no NO3 is added. CO2 is at 30ppm, k at 20ppm, PO4 at 1ppm and 5mls of trace added three times a week (tank is 80l). Small, low levels of dosing provided good growth, but this had to be carried out very often, otherwise the dosing produced algae blooms and/or nitrogen stunted plants. Even relatively small amounts of NH4 allowed to exist in the water column without the presence of nitrifying bacteria will trigger many algae species to bloom. Even a residual amount of NH4 for 30 hours can trigger a bloom.

When the test was carried out with no NH4 dosing, non limiting NO3 at 75ppm (high nitrate levels, I think we can all agree on) and PO4 at 1.2ppm, no bloom was triggered, even the tank had just been cured of the previously triggered algae bloom. When NH4 was added, the bloom reappeared (Barr, 2000). This is repeatable experiment that any aquarist can carry out.”

Nitrogen uptake at cellular level:

"Two forms of nitrogen are taken in: NH4 (the most reduced form) and NO3 (the most oxidised form). It takes 8 electrons to reduce NO3 in to NH4, which is one of the most energy expensive reactions that occur in plants. This is why NH4 is the preferred source when there is sufficient NH4.”

NO3 can be stored by plants, so at certain NH4 levels, NH4 preferrence may not be the case.

NO3- + 8H+ +8e => NH3 + 2H2O + OH-

“For those that choose to cycle a planted tank (not cycling is another avenue which may cause some consternation among senior members), whilst NH4 and NO3 can be seen to decline, NO2 does not decline until nitrosomonas bacteria are present. Plants can take up NH4 faster than NO3, but are not as adapted in the aquatic environment as algae.”

Do plants suppress algae due to NH4 removal?

“Low NH4 in an eco system is a good indicator of competition from another autotroph or an efficient nitrifying bacteria colony. Algae not blooming in high nutrient aquariums were the NH4 is efficiently removed by plants and nitrification is a correlation by many aquarists. Overload these tanks with NH4 and algae is triggered in to bloom.”

Many of us have seen this, and it is easily proven by those that haven`t witnessed it. If I add Zeolite to a new tank, brown diatoms never put in an appearance. I once believed it was due to silica levels, but this cannot be the case. All our tap water contains silica. All I do is remove the elevated NH4 levels experienced in most immature tanks, and never see brown diatoms. Recently, I had no Zeolite to start a tank, and witnessed brown diatoms once again."

“Myths and speculation over nutrient levels are easily put to rest through our own try it and see attempts in our tanks.”
 
#41 ·
All the pics below are of my tanks over the last three years or so. They all have pressurised CO2, T5 lighting and nitrates at 25ppm, phosphates at 4ppm, except for the last three pics which are of a recent tank with T8 lighting for slower growth rates. It is a 240l tank, which I don`t have the time to carry out heavy maintenance on.

Rotala rotundifolia




Rotala sp `Nanjenshan`







I never got to complete this one.









 
#42 ·
I notice in all of your pictures a considerable absence of fish. I realize that many aquarists prefer to focus on the plants, as opposed to the fish. For those of us who prefer to focus on the fish, how does the heavier bioload impact this entire conversation?
 
#43 ·
For those of us who prefer to focus on the fish, how does the heavier bioload impact this entire conversation?
not a great deal. the heavier planted the tank the heavier the bio load can be.
as stated one of the main causes of algae is ammonia. more plants = faster uptake

my 240 litre has
40 cardinals
2 angel fish
4 SAE
5 otos
6 corries
6 chain loaches
a 4" upside down catfish
and a 4" plec
 
#44 ·
Galvanize,

Am pleased with the growth in your tanks! they look awsome. Along the lines of Pasfur's question, Would reduced oxygen levels at night have an effect on large numbers of fish if one were so inclined to stock with two or three shoals of differing tetras for example? Please forgive me for any apparent ignorance but I was/am under the impression that plants use up oxygen during the night and thus,,the usually small numbers of fish in proportion to tank size. As stated ,I am willing and eager to learn new things but I confess,, fish are my primary love with regards to this hobby. Many thanks in advance.

Lee.
 
#45 ·
oxygen levels in the night don't really seem to be a problem.
personally i'd think the same issues apply in a "low tech" tank where little O2 is produced in the photo period due to very slow growth.
the water in a "high tech" tank is often totally O2 saturated long before lights out.
some ppl however do run an air stone for a couple of hours at lights out or right thro the evening to gas off excess co2.
 
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