Nitrate Test

[larochem595]

I bought the API Master Freshwater test kit.
Is it just me or does the 10 and 20 ppm colors look an awful lot alike? I can't really tell the difference between the two colors on the card. I don't have issues with any of the other tests, just the nitrates.

What do you use to test nitrates? Would you recommend it?
Thanks!
Michelle

 

[bud29]

They definitely are close in color; I find the API NO3 test relatively hard to read as well. I agree that the colors for 10 and 20 ppm seem almost identical. Like most people, though, I try to shoot for under 40 ppm nitrate - meaning that if I get the 10-20 ppm color, all it means is that I'm good.

 

[larochem595]

They definitely are close in color; I find the API NO3 test relatively hard to read as well. I agree that the colors for 10 and 20 ppm seem almost identical. Like most people, though, I try to shoot for under 40 ppm nitrate - meaning that if I get the 10-20 ppm color, all it means is that I'm good.

Ok, good...so its not just me!

 

[t57spikes]

I feel the same way, I wish there were distinct colors for each. Basically I aim for a light orange color and if it's ever red I know I need to fix it. I find the pH readings difficult also. Thinking about investing in a electrical instant read pH meter.

 

[larochem595]

I feel the same way, I wish there were distinct colors for each. Basically I aim for a light orange color and if it's ever red I know I need to fix it. I find the pH readings difficult also. Thinking about investing in a electrical instant read pH meter.

Now I know what I want for Christmas =)

I don't have quite as much as an issue with the pH...I wish I could tell 10 ppm of nitrates apart from 20 ppm...

Thanks for the reply,
Michelle

 

[trennamw]

Yes me too.

Doing a dilute test helps. It's free, if your tap has no nitrates.

Just fill the test tube up to the line with tank water, and dump it in a glass. Add 9 test tubes of tap water. Mix that up.

Then use that mix to fill the test tube up to the line, and do the nitrate test. Multiply the result by 10.

If you have two bucks you can get a pipette, or baby medicine dropper, and a bottle of distilled water. Do .5 ml tank water and 4.5 ml distilled, and again multiply by 10.

That's how I learned what 20 looks like (diluted it looks like 2).


Sent from my iPhone with three hands tied behind my back.

 

[larochem595]

I will say that the baby medicine dropper helps with the measuring--I can pull 5 mls out of my tank perfectly on the first try every time.






The dilute test sounds interesting and maybe worth a shot, though I would have to get bottled water.


Thanks,
Michelle

 

[jlk]

There is actually an easier way to discern lower level nitrate levels. The individual nitrate tests had quite different colored cards from the master kit a couple of years ago (same for the nitrite test as well). While the master kit card has greater distinction for levels above 40, the individual card is more distinct for levels below 40. The higher levels on the individual card all appear the same shade of red.

I am not sure if API still has different colored cards for individual versus master kits but it would be worth checking online. I will see if I can find a card somewhere tomorrow in my fish closet and post a picture of the differences to help everyone.




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[larochem595]

I will see if I can find a card somewhere tomorrow in my fish closet and post a picture of the differences to help everyone.
That would be awesome, thanks!

 

[jlk]

Hopefully, this picture attached! On the left is the section of the freshwater master test kit card. On the right is the individual freshwater card. With the master card, I have a hard time discerning between 5, 10 and 20ppm (they all appear orange). With the individual card, I can at least see a difference. Hope this helps!



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[trennamw]

I think those differences in the cards are because of the printing process.

It's extremely likely that the card with the frshwater kit is printed with CMYK inks (like your inkjet printer) and the card with the single kit is printed with an orange red ink. That's what would cost the least.

No telling which is more accurate. They're just different. I worked in printing for a decade and this is a common issue. There are so many colors that are impossible to represent on paper. Then they fade over time.




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[jlk]

I think those differences in the cards are because of the printing process.

It's extremely likely that the card with the frshwater kit is printed with CMYK inks (like your inkjet printer) and the card with the single kit is printed with an orange red ink. That's what would cost the least.

No telling which is more accurate. They're just different. I worked in printing for a decade and this is a common issue. There are so many colors that are impossible to represent on paper. Then they fade over time.




Sent from my iPhone with three hands tied behind my back.

Interesting information. However, in respect to accuracy, I think it's quite difficult to determine an 'accurate' assumption of what one's nitrate level 'may' be using the master card if your test tube shows up as orange. It's not a matter of 'different' nor would someone new to this test have any idea what to guess their level may be.

Although not overwhelmingly scientific, the individual nitrate card does in fact accurately reflect what my tap water reads based on tests from our water authority as well as private company testing. The master card does not.

The point of posting the pictures is to provide those that are having difficulty figuring out what their water 'may' be reading with some delineation between lower level ppm. The individual card does help with this and has greater accuracy based on my experience. Whether certain cards used different inks or were produced in less expensive fashion lacks relevance in determining if your nitrate level is 5 or 10 or 20, especially if the card your using to judge this shows all these levels as a single color.


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[larochem595]

Hopefully, this picture attached! On the left is the section of the freshwater master test kit card. On the right is the individual freshwater card. With the master card, I have a hard time discerning between 5, 10 and 20ppm (they all appear orange). With the individual card, I can at least see a difference. Hope this helps!

It definitely helps!
I just can't get over what a difference there is between the two... Either way, I think its time for yet another water change.

Thanks!
Michelle

 

[TomK2]

Yep. New card looked like a misprint to me. I can't tell those two values apart. But I think the drop amounts changed for nitrate compared to the old color cards? I use both, but in reality I keep nitrates down around 5 so it's moot.


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[trennamw]

Although not overwhelmingly scientific, the individual nitrate card does in fact accurately reflect what my tap water reads based on tests from our water authority as well as private company testing. The master card does not.

That's really good to know. And it makes sense that if you had a choice, you'd want the one from the individual test box.

Red-orange colors are especially difficult to represent on a CMYK sheet. Imagine trying to mix magenta and yellow just right, versus selecting an already red orange ink and varying its saturation.

Anyway. Since you sort of calibrated the test sheets against your water supply, that confirms what was most likely anyway.

We all should write API and tell them we'd be happy to pay 50 cents more for the master test kit if they would please include the individual cards instead of the one


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