# Adding 70ppm NO3 per week?



## wiijixx (May 22, 2013)

Hi everyone!
I have a little problem with my tank.
Tank description:
190 L (50 gal), presurized Co2, 200w (150w hqi 6500 + 50w T5 2700), 1000 l/h fluval filter. Kh5-6 Ph 6,5. 50% water changes per week (25% tap water 75% osmosis)
I'm trying to use Method of Controlled Imbalance: http://www.aquaticplantcentral.com/forumapc/algae/69737-method-controlled-imbalances-summary.html

I started with 1gr per day, then 2gr. Cyano(BGA) invassion and heteranthera turning black.
After a couple of month I had to re start my setup, because BGA.

I have re-started with a few plants and 3gr per day Kno3 (70ppm per week). Firsts weeks it was ok, but now BGA is growing again (but slower than with 1gr or 2 gr), and heteranthera getting black. In only just have a bit spot algae.
Questions are:
- is my kno3 pure?
- Does my plants eat too much nitrate? (and they have to grow x5 or x6 to finish setup, only 3 weeks setup)
- other?

Waht the hell is happing here?

Sometimes i connect an UV filter to get cristal water. Maybe it destroy kno3... dont know.

If this keeps happening, i'll have to increase to 4 or 5gr kno3 per day, but I think that this is too much salt in the water. isnt is?

Plz help me


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## Yo-han (Oct 15, 2010)

I mentioned it already in another thread but you've waaaay too much light. This way your CO2 demand will be at the top of what your fauna can handle or even more. At least more than you are supplying right now. I think it has nothing to do with the amount of NO3. If you want to be sure, throw in 100ppm of NO3 and see whether this works, throw in 10 ppm PO4 and you'll see the problem is not in PO4 or NO3, but in the light/CO2 balance.

UV does nothing with inorganic salts.


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## wiijixx (May 22, 2013)

Thanks for response!

Never thought that i had too much light. Maybe puting it farer? 

But... if i dont have enought co2, all my KNO3 will not be absorved...then green spot algae appear. But i dont see too much GSA in my tank....


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## niko (Jan 28, 2004)

Yes, the 'hqi' part in your original post is a thing to note. How many hours do you have it on?

Keep in mind that some bulbs can produce monstrous PAR. Your HQI bulb is probably doing exactly that plus those 2700K T5 bulbs do the same most likely. Add a lot of CO2 and of course you have to feed the tank like crazy. It's like driving too fast - a tiny error will lead to an immediate accident. If you want to play that game then accept the weirdness as normal.


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## Zapins (Jul 28, 2004)

So you are having a difficult time growing the heteranthera? Please post a close-up photograph of the affected plant and a few more photos of the other plants in the tank. It will help us to figure out what is going wrong in your tank.


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## wiijixx (May 22, 2013)

Hi, the problem was the method. I used Method of controlled imbalances, but i had tons of green blue algae. Hight phosphate or low nitrate if I fellow that method teory...

I bought some test and my nitrate was over 50ppm and P4 near to 0. There wasnt green spot algae in the tank, insteand tons os blue green and hetaranthera getting black and dieying. Kill that method.

No po4 or K added in weeks.... That method is very bad.

I had to use erithromicin to kill BGA and tank is cycling now again, because erythomic killed my biological media in the filter. 

Im trying to get 15 k/10 no3/1 p4 relation now in the tank, testing parametres every 3 days to see what nutrients are the plants absorving.....

Conclussion: dont use MCI (a lot of people said me this, but i dint believe them)


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## niko (Jan 28, 2004)

You are running after numbers. That's a big mistake. Because the tank will always change what you try to do. It will look like it works but it is you keeping the tank in balance instead of setting it up so it takes care of itself.

If you think that the Method of Controlled Imbalances is bad you should try EI. If you do not change the high light, tiny filter and start following EI you will see algae you have never dreamed of. Follow the advice of everybody that talks only about fertilizers and all your dreams will come true.

Good luck.


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## Zapins (Jul 28, 2004)

Interesting experience with that method.

I read through the first few pages of that thread and it seems like a lot of it is based on personal experience rather than actual tests. 

EI is a good method to use as long as you keep up with the required maintenance. It isn't totally algae free but it does a decent job most of the time. I use my own fertilizer method with lean trace dosing, and fairly lean macro dosing as well.


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## AaronT (Apr 26, 2004)

I fell into this trap recently as well. Dosing high levels of KNO3 like that also greatly elevates K levels, which I believe can block uptake of other nutrients.

I had Ludwigia inclinata var. inclinata stunting and growing maybe 2" a week under very strong lights and high CO2 levels.

I switched to this mix http://www.ukaps.org/forum/threads/for-dan-spezial-n-nitrogen-fertilizer.14594/ at the recomended dose and the Ludwigia inclinata took off growing about 5" in a week! Keep in mind that the N levels I was dosing before that were way higher, but all in KNO3 form.


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## Zapins (Jul 28, 2004)

Aaron you are adding the following mix?



> for one liter water add :
> 
> 25,9 g potassiumnitrate
> 29,5 g calciumnitrate
> ...


If so the difference you are seeing in plant growth is likely due to the Urea in the mix. Freemann and others have mentioned the difference urea makes in plants. I have been thinking about trying urea in addition to KNO3 since the benefits it offers seem to be quite substantial. I have a bag in my cabinet but I haven't used it since it can also promote some vicious green water I hear. Have you had any issues with green water yet?

Also I want to mention that the guy in that link seems pretty confused as to what symptoms he is seeing. The issues he describes are nitrogen deficiency symptoms not K toxicity at all. K toxicity is supposedly hard to achieve (though I will have to do some research on the exact levels). K toxicity would show up as curled/twisted/malformed new growth because it would block the uptake of Ca and Mg which cause curling.


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## Tugg (Jul 28, 2013)

Zapins said:


> If so the difference you are seeing in plant growth is likely due to the Urea in the mix.


Well it's official... I guess I need to piss in my tank when I get home. I have a sump, so at least I don't need a tall ladder.


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## Bert H (Mar 2, 2004)

So for all you chemists out there, what is the issue with urea and pH higher than 7? Will there be a reaction converting it to NH3?


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## Tugg (Jul 28, 2013)

Yup.
http://en.wikipedia.org/wiki/Ammonia_volatilization_from_urea

A lower pH slows the reaction and helps convert NH3 to NH4. Likely permitting your plants and filtration to handle it. On the plus with Urea, it apparently releases CO2  I would guess this is why there are reports of rapid increases of growth. You get the N and a CO2 source.


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## AaronT (Apr 26, 2004)

Zapins said:


> Aaron you are adding the following mix?
> 
> If so the difference you are seeing in plant growth is likely due to the Urea in the mix. Freemann and others have mentioned the difference urea makes in plants. I have been thinking about trying urea in addition to KNO3 since the benefits it offers seem to be quite substantial. I have a bag in my cabinet but I haven't used it since it can also promote some vicious green water I hear. Have you had any issues with green water yet?
> 
> Also I want to mention that the guy in that link seems pretty confused as to what symptoms he is seeing. The issues he describes are nitrogen deficiency symptoms not K toxicity at all. K toxicity is supposedly hard to achieve (though I will have to do some research on the exact levels). K toxicity would show up as curled/twisted/malformed new growth because it would block the uptake of Ca and Mg which cause curling.


Yes, I am adding fertilizer with urea now. I'm adding considerably less total N, but getting much better growth. That was the point I was making, but I guess not clearly. We often talk about how much N, but not what is the source of the N. Plants like different types and Ludwigias definitely LOVE urea.

Almost all of the commercial N fertilizers contain urea, ammonium or both. Seachem Flourish Nitrogen, Aquavitro Synthesis, Pfertz (not discontinued), and many others. Supposedly the Seachem ones are complexed so no free ammonia is released. You'd have to ask them if this is still true if your pH is neutral or above. Do yourself a favor and try one sometime and hold on to your trimming scissors. 

And YES, please do not add urea if your pH is anywhere near 7 or higher and a little bit goes a long way.


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## Tugg (Jul 28, 2013)

I have lots of ludwigias  It looks like this is used in hobby fabric dying too. Seems easily obtainable. When I eventually run out of KNO3, I'll be picking some up.


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## Zapins (Jul 28, 2004)

It is interesting to know the pH 7 bit of info. I wonder if this is what caused some people to have green water blooms? Plants do prefer ammonia > urea >>>> nitrate so it makes sense they would react well to it.

It is a real shame that the fertilator doesn't have a Urea calculator (or ammonia calculator, or certain iron, and potassium ferts). I wonder if we could add to the fertilator? Who programmed it anyway?


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## AaronT (Apr 26, 2004)

Zapins said:


> It is a real shame that the fertilator doesn't have a Urea calculator (or ammonia calculator, or certain iron, and potassium ferts). I wonder if we could add to the fertilator? Who programmed it anyway?


It's easy enough to do the math using molecular masses and whatnot. It would calculate for N though, which is not how are brains are wired. We're always talking about ppms of NO3 and PO4 when really it would be better to talk about N and P by themselves to compare to other sources such as urea or ammonium nitrate, etc...

For example the molar mass of molar mass of KNO3 is 101.10332 g/mol. Dosing to 1 ppm of NO3 gives you 0.225897 ppm of N assuming the chemicals used are 100% pure, which of course they are not, but it's close enough for our purposes.

The molar mass of CH4N2O is 60.05544 g/mol, which is very similar to NO3 on it's own and 46.6460 % of that is N so you need dose considerably less to get the same dose of N as you would when using KNO3.


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## AaronT (Apr 26, 2004)

So let's look at the mixture I've been dosing the past couple of weeks.

1,000 ml solution in which I mix

25,900 mg KNO3 13.8539% of that is N so 3,588.161 mg of that is N
29,500 mg Ca(NO3)2*4H2O 11.8626% of that is N so 4,399.467 mg of that is N
17,600 mg Mg(NO3)2*6H2O 10.9254% of that is N so 1,922.874 mg of that is N
5,000 mg CH4N2O 46.6460% of that is N so 2,332.300 mg of that is N

This gives us a total N amount of 11,342.7975 mg in the 1 liter solution

The recommended dose is 1 ml / 50 liters of tank water.

So one dose is 11,342.7975 / 1,000 = 11.3427975 mg of N

Adding that to 50 liters of water gives us 11.3427975 / 50 = 0.2269 mg / liter (mg/L = ppm)

For comparison adding enough KNO3 to bring NO3 up by 1 ppm gives you a dose of 0.2259 ppm of N, which is pretty darn similar.

Now the fun part is that the plants will grow A LOT faster with the mixture containing urea than they will with just KNO3 as the N source. Adding more KNO3 does not compensate for this. In fact I've only found it problematic because K levels get to be insane and I suspect they block uptake of other nutrients. Look at the water samples I sent Jeffy and you'll see when I was dosing EI my K levels were 100 ppm. It wasn't long after that I started having problems and I added more KNO3 hoping to compensate and things only got worse.

Keep in mind that if you decide to mix some of this up add a little ascorbic acid (vitamin C) to keep the pH of the solution low and stable. A little excel or potassium sorbate can be used as a mold inhibitor.

Of course the easiest thing to do is pick up a bottle of Seachem Flourish Nitrogen and give it a go. I guarantee you'll be hooked. 

Or if you want to try another way, simply get some Osmocote+ or other slow release fertilizer and put some underneath just one section of your tank and watch that section flourish while the other side is not as nice.

Helpful link for calculating molar mass: http://www.webqc.org/mmcalc.php


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## Zapins (Jul 28, 2004)

Great post. I'll be saving this one for later on.

K from KNO3 isn't a very large source of K. You probably got the K from other fertilizers. A lot of ferts use K as the cation so it is easy to accumulate it. In my tanks, as you can see from Jeffy's analysis, the K is nearly depleted completely and KNO3 is my sole source of N, I have to add in large amounts of K2SO4 to keep the K levels adequate. I would very much like to add urea as the nitrogen source, or part of the nitrogen source. I will let you know the results when I do.


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## Yo-han (Oct 15, 2010)

A 'little' off-topic but certainly interesting. Not in the last place because I experience slower growth in some plants and I blamed the higher dosages of excel I was giving. But I did raise the amount of K in the same period, thinking I couldn't overdose it. Perhaps I need to reinvest this and the use of urea as well


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## JeffyFunk (Apr 6, 2006)

Okay, so it seems this post has kinda gotten off topic (and my post is certainly not going to help any), but i have a question in general...

To AaronT - So you are now using the recipe that uses 5 g Urea? Didn't you comment on TPT that you tried using Happy's (i think that's his screen name...) recipe that used 7 g Urea and got green water? I remember doing the calculations myself for converting the Nitrogen in Urea to an equivalent amount of Nitrate and a little bit of urea is equivalent to a lot of nitrate...

Also, i measured your aquarium water as having [K] in the 100 ppm range. You said you reported stunting at these K levels, correct? Do you have samples of your aquarium water now that do not exhibit this stunting? I'm just trying to determine if i've seen the same problems in my aquarium since i've always thought that K is the missing element (in relationship to N & P, which can come from fish poop) so it was advised to always dose K first... maybe i'm just overdoing it...

To everyone - I always thought the nitrogen source in Seachem's Flourish Nitrogen was Guanidine Nitrate. Does anyone know if this is true or not? (Guanidine, (H2N)3C+ or (H2N)2C=NH2+, looks like Urea, (H2N)2C=O, but the =O group is replaced w/ an NH2+ group - it's always sold as a salt, usually with a chloride anion, but also with a nitrate anion... supposedly it's used in biochemistry labs a lot for protein denaturing...) I find Seachem's website description of Flourish Nitrogen with "complexed ammonia" to be strictly marketing speak (yes, it's not the free ammonium cation, but still...). They do say it's derived from: potassium nitrate, urea (iminium salt). Has anyone tried making a solution of guanidinium nitrate and seeing how it compares to Seachem's nitrogen or KNO3 or whatever?


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## Tugg (Jul 28, 2013)

Ok... Been reading and doing a little thinking. Won't urea raise our kH?

A mol of urea breaks down into 2mol of ammonium, 2 mol hydroxide, and 1 mol CO2. In water, won't the hydroxide and CO2 end up forming carbonates?

Now what about Ammonium Nitrate? It's less nitrogen per gram, but wouldn't it work better, providing both plant consumable sources and not effecting kH?


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## AaronT (Apr 26, 2004)

JeffyFunk said:


> Okay, so it seems this post has kinda gotten off topic (and my post is certainly not going to help any), but i have a question in general...
> 
> To AaronT - So you are now using the recipe that uses 5 g Urea? Didn't you comment on TPT that you tried using Happy's (i think that's his screen name...) recipe that used 7 g Urea and got green water? I remember doing the calculations myself for converting the Nitrogen in Urea to an equivalent amount of Nitrate and a little bit of urea is equivalent to a lot of nitrate...
> 
> ...


I don't think it's completely off topic. I was meaning to steer the OP away from the notion that more NO3 will solve supposed nitrogen issues. IME it only led to the same frustrations he experienced. The more I added, the worse it got.

I had the stunting a few weeks after I sent those samples so I suspect the K levels were even higher then.

I had some Aquavitro to try out so I'm currently dosing their full line of Synthesis, Activate, Envy, and Propel. So far it seems pretty nice.

The Flourish Nitrogen bottle says potassium nitrate, and urea are the ingredients. It lists K as a nutrient too so it can't be just guanidinium nitrate if there is any added.



Tugg said:


> Ok... Been reading and doing a little thinking. Won't urea raise our kH?
> 
> A mol of urea breaks down into 2mol of ammonium, 2 mol hydroxide, and 1 mol CO2. In water, won't the hydroxide and CO2 end up forming carbonates?
> 
> Now what about Ammonium Nitrate? It's less nitrogen per gram, but wouldn't it work better, providing both plant consumable sources and not effecting kH?


I'm not really sure, but it's possible. I've used ammonium nitrate as well and got results with that too.

The trickiest thing for me is that green algae like hair algae also seem to love ammoniacal nitrogen sources as well.


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## Cavan Allen (Jul 22, 2004)

AaronT said:


> The trickiest thing for me is that green algae like hair algae also seem to love ammoniacal nitrogen sources as well.


No problems here. Anyway, that's why there are shrimp.


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## Tugg (Jul 28, 2013)

Just bought two 2-packs of cold packs for under $4. Total weight was 480g (just over a pound) of ammonium nitrate. Let's see who wins, algae or plants. >=)


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## AaronT (Apr 26, 2004)

Tugg said:


> Just bought two 2-packs of cold packs for under $4. Total weight was 480g (just over a pound) of ammonium nitrate. Let's see who wins, algae or plants. >=)


Just go easy at first. More is not more in this case.


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## Zapins (Jul 28, 2004)

Tugg said:


> Let's see who wins, algae or plants. >=)


My $'s on algae!


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## AaronT (Apr 26, 2004)

I've added as little as 0.05 ppm N via urea in addition to my KNO3 dosing and seen a big improvement.


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## Tugg (Jul 28, 2013)

Ive been dosing shortly before my light do a noon burst, so hopefully the plants already be up and "awake" they can uptake it quickly.


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## wiijixx (May 22, 2013)

Hi!1 i lost this post for a long time! wow this is very interesting.
Has someioe tested spezial N fertilizing? results? 
Im think about to test urea....


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## Tugg (Jul 28, 2013)

AaronT adds a little urea and I'm using the ammonium nitrate (AN). I had to use excel to build a ghetto calculator for dosing since none of the common ones out there have AN. Urea will have the same problem.

I dose half my N from the AN, and the other half from KNO3. Since my pH is about 6.5 it should remain as ammonium and be relatively fish safe.

I haven't had problems with green algae, but BBA and BGA like to call my tank home. I think this is more of an organics issue from my wife overfeeding the tank though. I'm looking to rebuild my sump to remove the refugium and pumic and add a LOT more media (Moving Bed with MB3 that overflows through crushed lava rock and pot scrubbers.)
http://www.w-m-t.com/Products/WaterTek_MB3_Moving_Bed_Media.php


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## AaronT (Apr 26, 2004)

Tugg said:


> AaronT adds a little urea and I'm using the ammonium nitrate (AN). I had to use excel to build a ghetto calculator for dosing since none of the common ones out there have AN. Urea will have the same problem.


http://www.theplantedtank.co.uk/calculator.htm That one has urea and NH4

Have you noticed a difference in growth after starting the NH4 dosing?


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## Tugg (Jul 28, 2013)

H.polysperma hits the surface almost every week. A few sp of ludwigia seem to be getting healthier growth also, however I've been, and am still, dealing with N deficiencies. The NH4 helps I think. For people with a low pH, I say go with it.


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