# Planted Tanks > Fertilisation and Algae >  Nitrates in a planted tank

## vinz

In my planted tank (the one in this post), my nitrate levels are above 40 ppm. Last night it was up to about 60 ppm.

Bioload: 6 x Pearl Gouramis, 6 x Cories, 1 x Oto, Approximately 20 Yamatos. The water volume is approximately 45 gallons. I don't think I overfeed.

What's causing the high nitrate levels?
Is because the bacteria in my filter are too efficient or what?

----------


## oqs

too infrequent water changes? or what kind of fertilisers are you dosing your tank? maybe they contain the nitrates.

----------


## CK Yeo

Nope. i also dun think you overload. Nitrate dun come from no where. consider the few possibilities.
1) Over dose fertilizer
2) Substrate leeching nutrients (disturb?).
3) Faulty test kits (reference with water).

I wouldn't worry about it, unless it is constantly this high. If your tank healthy, it will drop very fast.
Change water if it bugs you.

----------


## vinz

These values are after water change and have been at the levels for quite a while. I do regular 25 to 30% water change every 2 weeks.

The plants are healthy, but the algae problem seems to getting worse.

----------


## CK Yeo

so none of the factors I pointed out is contributing to your nitrates? Please go check your test kit.

----------


## vinz

Actually, I've kinda suspected my substrate fert for a while... not sure how to verify that accept to take the plunge and uproot the whole tank and replace it. With a one month old son in my hands, that is not an option right now. Anybody got ideas with respect to testing this theory?

I've not checked the test kit (JBL) but have used it with another tank (unplanted tanganyikan cichlid tank) which registers undetectable levels of nitrates.

The liquid fertilizer has no ingredients printed on it... maybe I'll dilute some and use the test kit on it.

----------


## DEA

i think you're knee jerking too much
40~60 isn't that high
jacian had 80 regularly in his discus tank

but like CK says, change water if it bugs you
personally i know it's time to change the water when i have enough patience to sit there for 10 min waiting for the test to complete

----------


## MECH

hahahaaaa  :Razz:   :Razz:   :Razz:

----------


## wks

Don't worry about high nitrate, vinz. My nitrate is even higher &amp;gt;80 ppm. My guess is that the filter's bacteria is quite efficient in converting both food and fish waste. So to reduce the NO3 level, I normally use the lazy method: use floating plants. In my case, duckweed.  :Smile:

----------


## CK Yeo

WKS,

which also means that your bioload is sooooo high that the ammonium from whatever you dump in does not get taken up by the plants fast enough and the nitrifying bacteria have a chance to use it and convert it to nitrate. Ammonium at alkaline pH (i.e. when you turn off your CO2) will be majority ammonia, which is toxic (to plants and fish). Algae galore!
Duck weed is a double edged sword. while it sucks up nutrients in the water column, it blocks the light. The plants in the shade will not do well, and will not recover from the algae. 80ppm of nitrate is not good if it all came from fish load. Since nitrate is only one of the things that we test in the aquarium, can you imagine all the other things that we dun test to build up in your tank even if you change 20-30% everyweek?

----------


## wks

Well CK, my plants and fish are still doing well, in fact they grow taller and fatter respectively. As for duckweed blocking the light, the plants which I have are mainly low light ones. My problem is the java ferns, vals and crypts are growing very well under shade that I have to prune them sooner than I expect. :Smile:

----------


## buzzmario

hi there, mario here, new member.
well would like to know what is ther right level of nitrate in a plant tank?
how the test kit work?

thank

buzz off ... from mario :Wink:

----------


## CK Yeo

> ----------------
> On 2/24/2002 1:29:07 AM 
> Well CK, my plants and fish are still doing well, in fact they grow taller and fatter respectively. As for duckweed blocking the light, the plants which I have are mainly low light ones. My problem is the java ferns, vals and crypts are growing very well under shade that I have to prune them sooner than I expect. 
> ----------------


Good for you. If you found the "balance" and there are no major algae problems, I suppose no one can say that maintaining this high levels of nitrate is no good? But this level of nitrate may not work under different tank conditions.
Mario,
there is no "right" level of nitrate... what is recommended is &amp;lt;40ppm and it should drop pretty fast after dosing. but this depends on the types of plants and the setup that you have.

----------


## DEA

in general, the lower the nitrate the better, but getting zero nitrates means your plants are lacking in nitrogen
and as for high nitrates, 80 isn't considered very high yet
i wouldn't worry about it unless your fish are visibly listless or getting infections of all sorts

----------


## CK Yeo

> ----------------
> On 2/24/2002 2:10:45 PM 
> in general, the lower the nitrate the better, but getting zero nitrates means your plants are lacking in nitrogen
> and as for high nitrates, 80 isn't considered very high yet
> i wouldn't worry about it unless your fish are visibly listless or getting infections of all sorts
> ----------------


Not entirely true. If your tank zero in nitrate doesn't mean your plants zero in nitrogen. the water column is not the only place for plants to grab nitrate from. You can have zero nitrate but plants not nitrogen deficient. izn't that why we put fertilizer tabs at the roots? fertilizing the water column is NOT the only way to feed plants. You will not know if your plants are really nitrogen straved unless you do a tissue analysis. but generally, plants show signs of it when they are nitrogen starved.
80ppm is not high? should wait till fish get stunned growth, algae bloom to consider it as high? fish will probably never experience this amount of nitrate in nature (unless they live in the sewers).
While I sometimes dose high amounts of nitrate, it should drop to zero within a peroid of time and will stay constant at the initial dosing concentration. Again, this is subjective to the tank conditions that you have... but I definitely do not advise to maintain a constant nitrate concentration of 80ppm generally, or start pouring KNO3 into tanks once the water have zero nitrate. Neither nescessary or encouraged.

----------


## DEA

hmm, i amend that to "the water column is lacking in nitrogen"
din think of that

how can you say high or not high? have we done any studies of nitrates on fish physiology?
until then, we can only give anecdotal measures of nitrate levels being high or not
fact is, ppl have fish thriving and even breeding in water with 80ppm nitrates
this is what i base my comment on

----------


## CK Yeo

WHO state drinking water NO3 values at 50ppm. While it is true that nitrate is relatively low in toxicity compared to ammonium and nitrite, it is not necessary to maintain (note: not dose) this level of nitrate, especially in a planted tank. What I can say is that, if this level of nitrate works for your tanks and your fish are thriving/breeding, good for you. But it is not a concentration I would advise everyone to maintain at.
Again, I would like to re-emphasize that nitrate is only one of the parameters that we can measure conveniently using test-kits. imagine the all the other parameters that we can't measure and the effects of those in your tanks. Which is why we change water (and again, this is controversial)... :Smile: 

p.s. I thought we were talking about planted tanks?

----------


## DEA

we are, aren't we?  :Smile: 

you bring up a very interesting point
amano DOES measure some parameters that aren't commonly quoted in the aquarium hobby
one i can think of is COD, chemical oxygen demand

and i'm oso a proponent of frequent water changes, yes

----------


## CK Yeo

Really? So what does COD tells you about the aquarium? Does Amano do BOD as well?
Interesting that you mention that you advocate water changes but maintain high nitrate and add salt to planted tanks. What other "non-standard" things to you do?

----------


## DEA

> ----------------
> On 2/24/2002 9:11:51 PM 
> 
> Really? So what does COD tells you about the aquarium? Does Amano do BOD as well?
> Interesting that you mention that you advocate water changes but maintain high nitrate and add salt to planted tanks. What other &amp;quot;non-standard&amp;quot; things to you do?
> ----------------


1. my tanks don't have high nitrates
what i'm saying is 80 isn't high enough to make one lose sleep
if you can find one single statement by me advocating adding nitrates, please tell me so i can delete it

2. i add salt to fight ich and chilodonella
once it's gone i change the water out

3. COD tells you how much organic waste there is in the water

what's BOD?

----------


## DEA

ahh, i remember, biological chemical demand
i can't remember how to test for it though
i imagine that COD &amp;gt; BOD

----------


## wks

Hi CK, I think the parameters vary from tank to tank. The most important thing I feel is to observe our plants and fishes. They will tell us whether those parameters which we discussed are suitable in the tank now. If everythings OK, hands off. If not, we have to check and adjust accordingly. Guidelines(come with factor of safety) are useful for novice hobbyists who need proper info to set up and maintain aquariums safely. Once u cross that stage, its up to u to experiment with your tank. :Smile:

----------


## CK Yeo

> ----------------
> 1. my tanks don't have high nitrates
> what i'm saying is 80 isn't high enough to make one lose sleep
> if you can find one single statement by me advocating adding nitrates, please tell me so i can delete it
> 2. i add salt to fight ich and chilodonella
> once it's gone i change the water out
> 3. COD tells you how much organic waste there is in the water
> ----------------


1) which is why I asked if we were talking about planted tanks. From the eariler replies, I got the impression that 80ppm on nitrate in planted tanks are norm. Thank you for clarifying that. Of course, 80ppm in freshwater fish tanks are ok, but in planted tanks, that is something else altogether.
2) from another thread, I got the impression that you maintain salt in a planted tank. Maybe it is my misunderstanding. In that thread, I was refering to long term effects of salt in tank. Just out of curiosity, how long do you keep salt in the tank?
3) so what if COD&amp;gt;BOD?
4) relac... just a hobby.

----------


## DEA

> 1) which is why I asked if we were talking about planted tanks. From the eariler replies, I got the impression that 80ppm on nitrate in planted tanks are norm. Thank you for clarifying that. Of course, 80ppm in freshwater fish tanks are ok, but in planted tanks, that is something else altogether.
> 2) from another thread, I got the impression that you maintain salt in a planted tank. Maybe it is my misunderstanding. In that thread, I was refering to long term effects of salt in tank. Just out of curiosity, how long do you keep salt in the tank?
> 3) so what if COD&amp;amp;gt;BOD?
> 4) relac... just a hobby.
> 
> ----------------


1.  :Smile:  that's the problem with the internet u see
2. no no, it's just that my plants tided over the salt dosage (which is very extreme, but the problem was extreme too) without any problems
3. it would imply there's no need to measure BOD if you already know the COD (cos safer to take the higher value)
4. [ :Grin: ] very relaxed liao

----------


## CK Yeo

> ----------------
> On 2/24/2002 10:59:54 PM 
> Hi CK, I think the parameters vary from tank to tank. The most important 
> ----------------


I agree 101%... as long as the method works for you.  :Smile:

----------


## CK Yeo

> ----------------
> 3. it would imply there's no need to measure BOD if you already know the COD (cos safer to take the higher value)
> ----------------


I very dense. but.... So? COD very high... what will happen?

----------


## vinz

Ok, now I'm lost... after the long debate between CK Yeo and DEA.

I'm having algae problems which seem to be getting worse. I thot it could be due to excess nitrates.... or at least i thot it indicated the lack of some other nutrient is limiting the nitrate intake. I've tried K (potassium) for a week, but results are unnoticable.

One of my gouramis seem to be dying... lying at the bottom of the hospital tank gasping. Suspecting gill disease or damage? My cories who used to be active first became agitated, then now seem to have dissappeared... unable to find any dead bodies. Occassionally can find one hidden in the undergrowth.

Could all this problems be due to high nitrate values?

Also discovered that my anti-chlorine binds heavy metals 
[:0]. So got to change that.

----------


## vinz

Newly replanted MMs and APP are dying out too. The leaves turn translucent and then the plant dies...

----------


## loupgarou

nitrate toxicity at 100 - 300 gm/l . doubt you ever hit that.

you will have a bba problem way before that happens. heh

----------


## CK Yeo

> ----------------
> On 2/25/2002 3:07:24 PM 
> Could all this problems be due to high nitrate values?
> ----------------


sheesh! cannot say high nitrate! wait DEA humtum you also.  :Razz: 

Anyway, in your original question you asked why your nitrate so high. I think I missed out one possibility which wks pointed out: your filter. 
When was the last time you cleaned it?
If still cannot troubleshoot, then i dunno what already.

----------


## loupgarou

http://www.csd.net/~cgadd/aqua/art_plant_nutrient.htm

----------


## DEA

> ----------------
> On 2/25/2002 3:13:08 PM 
> 
> Newly replanted MMs and APP are dying out too. The leaves turn translucent and then the plant dies...
> 
> ----------------


is there anything new you've been doing? or this just happens all of a sudden?your nitrates could be increasing because your plants are not healthy, thus not using up ammonium, which then goes to the bacteria
clean out your filter and do water changes, that could help
add some root fert
and if you wanna try, pflanzengold-7 is supposed to work miracles on plants like those you mentioned which are stagnating for no apparent reason

high COD implies the water contains organic/inorganic substances that could use up oxygen and turn the water anaerobic
in some cases i've seen the fish gulp for air even with no CO2 injection
mostly it's corrected by a filter cleaning and water changes

chris, the nitrate toxicity, where you get from? can email or whatsoever, i wanna take a look [: :Smile: ]

----------


## benetay

Yes GOLD-7 works wonders on plant ...

----------


## CK Yeo

> ----------------
> On 2/25/2002 3:51:35 PM 
> high COD implies the water contains organic/inorganic substances that could use up oxygen and turn the water anaerobic
> in some cases i've seen the fish gulp for air even with no CO2 injection
> mostly it's corrected by a filter cleaning and water changes
> ----------------


I dun wan to get into another debate regarding COD and BOD, but I am more a plant person than a fish person. And since we are at a plant forum, can you explain a bit about how COD affect plants (or algae)?

----------


## DEA

dunno
never bothered to find out
just noe it's not good for fish

----------


## wks

vinz, have u counted your fish? If many fishes died and not taken out from the tank, that is going to contribute to the rise in NO3 due to decomposition. :Smile:

----------


## vinz

The high levels were before any deaths.
Right now I have 6 cories missing and I have yet to find them.

----------

