# if you dose KNO3 and have nitrate test kit Help me



## lithevantim (Feb 10, 2010)

Hi there,

I recently bought KNO3 (potassium Nitrate) from another member and when i added some to a sample tap water and tested it with my nitrate test kit it dosen't indicate any nitrate in the sample.

This test kit has always been accurate, so does this mean i have actually bought something else and not KNO3 (potassium Nitrate)

I really need to know asap because i have to make up my fertz tomorrow.

If anyone could test a little bit of their potassium nitrate in a sample of tap water with their nitrate kit and tell me the result i would really appreciate it.

thanks so much

Tim


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## tug (Jul 23, 2009)

Nothing? Did you check your test kit on something like your tank water?


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## lithevantim (Feb 10, 2010)

My test indicated 0 nitrate for the sample. When i tested my other tank it indicates nitrate 15.

If anyone could test there KNO3 and see what happens i would really appreciate it.

Thanks


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## wearsbunnyslippers (Feb 18, 2008)

how much kno3 did you add to how much water for your test sample?


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## wearsbunnyslippers (Feb 18, 2008)

you can test if it kno3 by making touch paper

disclaimer: i take no responsibility for you burning your house down, setting your cat on fire etc. with this recipe...


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## Seattle_Aquarist (Mar 7, 2008)

Hi lithevantim,

I had the same problem and couldn't figure out why I could not get a reading. I even went so far as to add NO3 to the test tube and test....still 0 ppm! I bought fresh KNO3.....still 0 ppm. Finally I called API customer service and got the answer, and did I feel foolish!

The problem was me and not following the instuctions. Prior to the test I shook up the two bottles of reagents to make sure they were well mixed then I thought I followed the instuctions but I was messing up on a couple of the steps!

API Nitrate Test Instuctions:

Directions for Testing Nitrate:

* Read thoroughly before testing. Do not allow Test Solutions to get into aquarium.
* To remove childproof safety cap: With one hand, push red tab left with thumb while unscrewing cap with free hand.
o Fill a clean test tube with 5 ml of water to be tested (to the line on the tube).
o Add 10 drops from Nitrate Test Solution Bottle # 1, holding dropper bottle upside down in a completely vertical position to assure uniformity of drops added to the water sample.
o Cap the test tube and invert tube several times to mix solution. Do not hold finger over the open end of the tube, as this may affect test results.
* o Vigorously shake the Nitrate Test Solution Bottle # 2 for at least 30 seconds. This step is extremely important to insure accuracy of test results.*
o Now add 10 drops from Nitrate Test Solution Bottle #2, holding dropper bottle upside down in a completely vertical position to assure uniformity of drops to the water sample.
o *Cap the test tube and shake vigorously for one minute. This step is extremely important to insure accuracy of test results.*
o Wait five minutes for the color to develop.
o Read the test results by matching the color of the solution against those on the Nitrate Test Color Chart. The tube should be viewed against the white area beside the color chart. Color comparisons are best made in a well-lit area. The closest match indicates the ppm (mg/L) of nitrate in the water sample. Rinse the test tube with clean water after each use.

And that was my problem, I wasn't shaking Bottle #2 prior to adding the drops. When I shook Bottle #2 prior to adding the drops and I shook the test tube for 1 minute prior to letting it sit; I got proper results. I felt foolish but it isn't the first time I have felt that way and it won't be the last I am sure.

Hope this helps solve you problem!


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## tug (Jul 23, 2009)

Sounds as if they sent you a bag of the wrong stuff. Did you ask them if they inadvertently sent you a bag of something else by mistake? Maybe you have a bag of KH2PO4 or GH booster. Do you have a scale, unfortunately weight per one teaspoon are pretty close;
Potassium Nitrate 6.0g
Potassium Phosphate 6.6g
Potassium Sulphate 5.1g
GH booster ~ 4.8g


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## ObiQuiet (Oct 9, 2009)

Seattle_Aquarist said:


> Vigorously shake the Nitrate Test Solution Bottle # 2 for at least 30 seconds.


Just because that's how I am, I thought I'd test this scientifically.

Same water sample, same test solutions. Only difference was the shaking, in three variables: Bottle 1, Bottle 2, and the final mixture.

Indeed, the key to getting a non-zero reading is shaking Bottle #2.

Shaking the whole mixture is important too, but doesn't make the night-and-day difference that Bottle #2 makes.

-ObiQuiet


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## Seattle_Aquarist (Mar 7, 2008)

Hi ObiQuiet,

LOL! Nothing like admitting I messed up in front of everyone! I just hope it helps someone else avoid all the hassle I went through just because I did not follow the directions correctly. 

Thank you for confirming that it was my error that caused the problem, LOL! It is important for me to be able to laugh at myself.


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## ObiQuiet (Oct 9, 2009)

That's funny.  I wasn't even thinking about what _your_ reaction to my post might be... I did the test only because if I was going to put in the extra effort and time to shake that little bottle, I _need_ to know there's a point to it. I don't blindly follow directions unless I believe in them, especially if they make me feel silly....


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## LigouriRd. (Jul 14, 2010)

I guess i have been making the same mistake. So now the questions is, have I made the test solution further not accurate by drawing off some of the #2 solution without shaking it? I have made probably about 6 tests since buying the kit.

No wonder I keep reading 0ppm...frell I have been adding a ¼tsp of KNO₃ for the past few days...I wonder what my nitrate reading really is?


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## Seattle_Aquarist (Mar 7, 2008)

Hi LigouriRd.,

I am glad to see I am not alone! Your test solution #2 is probably still good to use after only making six tests without shaking. I did buy a new test kit (I did probably 15+ "bad tests") and my new test kit read the same as my old test kit once I did it correctly.

If your nitrate level is high, do a 50% water change then wait a day, do a test, if it is still high do another 50% change. Between the water changes and what the plants use the nitrogen level will drop fairly quickly.


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## virgo888 (Jun 25, 2009)

yup. shaking bottle 2 is the key.


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## Gramazing (Mar 6, 2010)

What does everyone recommend as a good nitrate level for a moderately planted tank?


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## Seattle_Aquarist (Mar 7, 2008)

Hi Gramazing,

I try for about 20 ppm of Nitrates.


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## virgo888 (Jun 25, 2009)

my tanks are at 25-30ppm nitrates and works for me.


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## tug (Jul 23, 2009)

4ppm to 30ppm but try to keep it in a range of 5-10ppm. Use the recommended EI doses and you shouldn't have a problem.


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## Gramazing (Mar 6, 2010)

Mine's about 20ppm by the end of the week, and I'm dosing for a 20-40 gallon tank on my 55.


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## Diana K (Dec 20, 2007)

I aim for 5-10 ppm as a minimum, and do not worry until it hits 20 ppm. 
Low tech tanks, so most of the nitrate is from decomposing fish food. This seems to be harder on the fish (Or is it something else that happens concurrently?) than raising the NO3 level with fertilizers.


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## davejt (Nov 22, 2009)

I've had the same issue with this test kit. you _have_ to be sure to do the shaking or you get the wrong reading it also makes me wonder, though I never called API about the accuracy as you get to the end of the bottle. As in if you forget to shake it for a few tests over the lifetime of the bottle, does the concentration of something in the solution change?

At any rate I have been using Seachems test in conjunction with API's for some time now and I think I will stay with the Seachem test for the future. It's not instant read, but you don't have to worry about pre-mixing the reagents. FWIW.


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## trag (Jan 9, 2008)

I calibrated my API nitrate test kit this weekend and found that it reports about half of the actual concentration (10ppm reading for a 20ppm solution; 20ppm reading for a 40ppm solution).

Additionally, I found that above about 100ppm all the solutions produce the same color -- the 40ppm indicator color. I never could get the 80ppm nor the 160 ppm color, even when I tested my 2000ppm solution.

I used Rex Grigg's instructions Nitrate Calibration Solution but mixed up a 2000ppm solution to start (1.631g in 500ml H2O) because my squeeze bottles are 500ml. Then I made a 200ppm solution, etc. I wrote down each step before I did it, to double check my math, so I'm pretty sure I didn't accidentally make a bunch of half strength solutions.

It's still possible that I goofed along the way. I assume Rex's instructions are good, but I guess I could look up the molecular weight of KNO3 to be sure. Another possibility is that my KNO3 is only half pure. I bought it on Ebay for non-aquatic purposes, but the seller had plenty of reviews and the pyrotechnics guys would notice if it was less than 90% pure.

Anyway, the API test does not appear to be especially good to me.


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