# Dry Fertiliser Dosing & Nitrite



## mark4785 (4 Jan 2011)

Hello,

I was recently referred to this website by the owner of a company named Fluidsensor who supplied me with the dry fertilisers needed to start an estimative index dosing regime.

I purchased from him, the following to make to two separate forms of nutrient solution:

*Macro-nutrient Dry Chemicals:*

-Potassium Nitrate
-Potassium Phosphate

*Micro-nutrient Dry Chemicals*

-Trace elements consisting of Fe 8.4% (EDTA), Mn 1.82% (EDTA), Zn 1.16% (EDTA), B 1.05%, Cu 0.23% (EDTA), Mo 0.15%
-E300 Absorbic Acid

I mixed the dry macro-nutrient substance into a container of 250ml DI water and did the same for the micro-nutrient substance.

After doing this, I have been following a typical EI dosing regime which involves doing the following from day-to-day:

Sunday 	50% water change. Add Macros (KNO3, KH2PO4)
Monday 	Add Traces
Tuesday 	Add Macros (KNO3, KH2PO4)
Wednesday 	Add Traces
Thursday 	Add Macros (KNO3, KH2PO4)
Friday 	Add Traces
Saturday 	Rest day

I have been adding 13ml of macro-solution on the designated days shown above, which equates to just above 8.5 ppm of nitrates added 3x a week.

I have been adding 10ml of the trace/micro-nutrient solution 3x a week too.


Right, now, it is understood what dosing regime I'm using and what chemicals are involved with it, I'd like to describe the concern I have.

Ever since starting with EI dosing involving the chemicals above, my API freshwater nitrite test kit has been indicating that there is anywhere between just over 0 ppm of nitrite in the water to just over 0.50 ppm. The aquarium has been established since August 2010 following a fishless cycle and hasn't seen a visibly fluctuating nitrite level until I started EI dosing.

Could somebody please tell me if the aquatic life in my tank is in immediate danger of death due to a real nitrite issue OR whether the nitrite test kit is incompatible with the nutrient solution(s) causing an inaccurate reading??

Thanks,

Mark.


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## ceg4048 (4 Jan 2011)

Hi,
   Nitrite, Nitrate and Phosphate test kits are complete rubbish and should be thrown in the tip. Using test kits does not help you to grow plants and they often deceive. The inaccuracy of these kits have nothing to do with the nutrients in the tank. These test kits are faulty and tell lies regardless of whether you are dosing nutrients or not. I suggest that you stop spending money on test kits and instead observe your tank. Learn and understand the behaviour of your fish so that you will be able to recognize unusual behaviour. Observe the plants so that you will understand the normal growth patterns and will be able to recognize unusual growth patterns.

Cheers,


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## mark4785 (4 Jan 2011)

Thanks for the response,

Please can I get a second opinion as I don't believe nitrite kits are totally rubbish. After all, they are a crucial tool used in the fishless nitrogen cycle when setting up an aquarium.

The question I really need to get the answer to is do the substances involved in EI dosing cause API nitrite test kits to show very inaccurate nitrite concentrations or is there actually nitrite in the substances?

Mark.


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## RudeDogg1 (4 Jan 2011)

Ceg is pretty much one of the dons on here so if he says they are rubbish then he's prob right. Most test kits are very vague so he is right I'm afraid.


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## mark4785 (4 Jan 2011)

Let me word it differently; if nitrite test kits are inaccurate without fert dosing, then do they become more inaccurate with fert dosing?

"The question I really need to get the answer to is do the substances involved in EI dosing cause API nitrite test kits to show very inaccurate nitrite concentrations or is there actually nitrite in the substances?"


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## a1Matt (4 Jan 2011)

I think these 3 statements give you the clarification you are after:

There are no nitrites contained in the substances you are dosing.

The results of the nitrite test kit is not effected by the dosing of dry ferts.

Any innacuracies you are therefore seeing in your nitrite results (and I bet that is what you are seeing) are inherent in the test kit and not related in any way to the substances you are dosing.

Further...

If you do not want to take others word for this, you can gain experiental knowledge by making up a calibrate solution and use that as a reference point for your kits.  If you google 'tom barr calibration solution' you will get all the info you need to do this. You will then see that some kits (I am referring to types of kit. i.e. kno3, or kh, etc rather than specific manufacturers) are not all that bad, whilst others are so shockingly useless it makes you wonder how they have the gall to sell them in the first place...


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## mark4785 (4 Jan 2011)

But the nitrite test kit has never indicated anything above 0ppm in the 6 months I've add it. It's only started showing higher levels of nitrite since I started using these new substances. I find that very very strange.

I will do that Google search shortly and see what I can do.


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## nry (4 Jan 2011)

I'm sure I've read somewhere of some chemicals giving a false nitrite reading but I can't find anything anywhere that rings a bell.  I think it was perhaps one of the water treatment products from SeaChem but I may be wrong.

Are you getting any ammonia readings?


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## CeeJay (4 Jan 2011)

Hi mark4785.

You will find that as your knowledge evolves in this planted tank game that hobby grade test kits are totally unreliable. You'll need to spend some serious bucks to get anywhere near an accurate one. My test kits went in the bin a long time ago. The condition of your plants and health of your fish should be the only test kit you need, and you can see that with your own eyes  .



			
				mark4785 said:
			
		

> I purchased from him, the following to make to two separate forms of nutrient solution:
> 
> Macro-nutrient Dry Chemicals:
> 
> ...


You can save yourself some pennies too. You do not need E300 Ascorbic Acid unless you are mixing the Trace with the Macros and, as you are not mixing the two, you don't need it . One less thing to buy


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## mark4785 (4 Jan 2011)

Hi Nry,

No the ammonia level is 0 ppm.

There hasn't been a total ammonia spike, so this tells me that the bioload isn't causing the nitrite level increase. It seems more like either nitrite has been directly added to the aquarium OR something is interfering with the API nitrite test kit (the latter is more probable because the sensitive fish I have would be near dead if it was the former).

As said above, I'm 99.9% certain my nitrite test kit is working absolutely fine as it's never given such a jaw-droppingly unexplainable reading before until I started EI dosing.


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## a1Matt (4 Jan 2011)

I'm still confident that the salts are not adding nitrites to your tank 
It sounds like you are pretty confident that the dry ferts are creating a false reading in your test kits (this is putting aside any debate concerning the validity\calibration\necessity of the test kits).

You could add dry salts to Ro\DI\purified water and then test those solutions with the nitrite kit.
Using this method you should be able to isolate any salts that are causing false readings.
If you decide to do this I would be interested to see what results you come up with.


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## Gfish (4 Jan 2011)

*Dry Fertiliser Dosing & Nitrite*

Mark

It's enough to mash your brain to a pulp, all this water chemistry, testing and dosing EI mullarky! I'm a relative newcomer to it myself, so I know how you're feeling.

What Clive and others here will tell you is to learn from things you can SEE in your tank, rather than things you READ from books and test kits. You know that saying....."
I wish I'd bookmarked it, but I read an extensive piece online recently which included, which nutrients plants take up and the varying rates and requirements of a list of common aquarium plants. It was fascinating and I felt like a nerd for being so engrossed! Lol 
Initially I was particularly interested to read of which plants eat nitrates more than others. But what I learned is that many plants will use up available nitrates, but actually have a strong preference for nitrites and ammonia. This was a bit of a revelation for me, and especially as we as aquarists work at good filtration to combat all ammonia and nitrites and to keep nitrates to a minimum, for the health and wellbeing of our fish. 
I think there's a certain level of filtration that is good for both plants and fish. In other words, no matter what your test kits read on nitrite and ammonia, there will always be occurrences that cause these to exist. They are dealt with by the filter media of course but perhaps they are dealt with quicker by a healthy and heavy planted tank a little quicker????? if you did not wish to keep fish, there'd be little need for even having a filter filled with media. A tank designed the right way can thrive without one apparently, and reading of the Diane Walsted method (look it up) has been very interesting!

Anyway, what I noticed when I added to and improved filtration on my 5ft tank (before I was using CO2 and dry ferts) is that plant health rapidly went downhill. This taught me something the text books don't touch upon and I now think of the ammonia cycle in a different way and I do not worry so much about testing the levels as I used to. I have healthy plants, so why should I worry, they'll be doing a good job 

The one way I got my head around adding spoonfuls of chemical salts to my tank was that these are clean nitrates and phosphates, not rotting leaves, fish poo and even rotting livestock. So it doesn't bother me adding the salts, so long as I'm seeing the plant health improving or remaining strong I feel I'm enabling the plants to take up both clean nitrates and phosphates I add, as well as use up dirty nitrates and phosphates that exist in the Eco system that is my tank. 

I've waffled on a bit here but I hope some of it makes sense and helps you to come to terms with some of the modern thinking on planted tanks here. I can't remember the last water test I did by the way 

Cheers

Gavin


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## RudeDogg1 (4 Jan 2011)

I have read befor that nitrAtes can screw with nitrIte test kits so maybe thats what is happening


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## dw1305 (5 Jan 2011)

Hi all,


> You will find that as your knowledge evolves in this planted tank game that hobby grade test kits are totally unreliable. You'll need to spend some serious bucks to get anywhere near an accurate one.


 I've worked in a water lab. and this is true for ammonia, nitrite and nitrate. I'm not sure about hobby kits, but you can use a colormetric assay for nitrite, where the nitrite (NO2-) ion reacts with NED dihydrochlorite reagent to form an azo dye, but it is very difficult to get consistent results at low nitrite concs.<http://www.asaanalytics.com/nitrite.php>. 

Because of the problems of effectively measuring fixed nitrogen in rivers and ponds you usually use the combination of BOD (Biochemical Oxygen Demand) of a water sample and a biotic index (basically a survey of the invertebrates) at the site to estimate the degree of eutrophication of a water body.

Water companies use HPLC (High Pressure Liquid Chromatography) and AAS (Atomic Absorption Spectrophotometry) for their water testing.

cheers Darrel


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