Difficulty reading Nitrates on AP Master Test Kit

[donttaptheglass]

I've always had really good vision, and have never been diagnosed with any kind of color blindness, but I'm starting to question it.

Am I the only one that sees almost no color difference on the Nitrate card on the AP Master Test kit between 20, 40 and 80 ppm? I see a difference in the 160 reading, but not much of one. I ask because I just did a test and I'm falling somewhere in one of those three, but having a real hard time telling the difference.

I'm doing a PWC in an hour or so, nonetheless, so maybe I'll know which it was on the test afterwards, but I just don't have this problem with the other three tests in the kit.

 

[Apocalypse_Gold]

I can sometimes see a difference between 20 and 40, but above that, forget it. If my nitrates are high I cut it 50/50 with ro or distilled water so that it is down in a readable range.

 

[tropicfishman]

yeah I can barely tell a difference in the colors myself, I figure if it gets that high it doesn't matter what the readings are, you just needa do a water change lol

 

[Fishyfanatic]

I agree with TFM. If the levels are high enough that you can't distinguish the color, it's time for a large water change.

 

[Jchillin]

I figure if it gets that high it doesn't matter what the readings are, you just needa do a water change..

Sound reasoning there tropicfishman, above 20 requires a PWC. When you get into the really blended colors on the chart, something is really wrong.

Prior to that method, I used to have my better half check the results...much better eye for colors of the spectrum.

 

[donttaptheglass]

Ok, thanks . . . yes, I just did the PWC, so I'll take a reading again in a few hours to see if its readable, I just wanted to know if I was the only one that thought those colors were awful close to each other.

Anyone recommend any other test kits or methods that are easier for them to use/read?

 

[tropicfishman]

I prefer the API kits, i've always used them and they have always been faithful, Hagen has a kit thast pretty easy to read though

 

[nitrous]

ya i had problems with the nitrate test kit alos its hard to tell from 0 to 5 and 5 to 10 or any of them at that and you have to do that test exactklly like the directions for all the shaking and when i didnt i got 0 each time but i think its bad that the most difficult test out of the kit is somewhat the most important to do and distinguish

 

[Lonewolfblue]

I'm currently using the Hagen Nitrate test kit, which does seem a little easier to read. AP is just too hard for me to tell the color because they are too close.

 

[rich311k]

I fine the Hagen test much easier

 

[TomK2]

Yep, those darn color charts! You are not alone.

 

[jsoong]

I can't tell with any of my Hagen test (NH3, NO2, NO3) what levels it is actually reading. The color reproduction on the charts is terrible, and a lot depends on the light (I get different colour in sunlight vs. incandescent vs flourescent light .... maybe it is just my bad eyes!)

For the NH3 & NO2 test, I treat it as a yes/no test. If I see any colour, it is bad, a hint of colour - trace, kinda bad. I get an idea of how bad by serial dilution ... I take out one ml of the solution, and add pure water one ml at a time until I just have a hint of colour. If I have to add say 9 ml of water, then it is 10x trace (in that case I need to do a 90% PWC to bring the level to trace).... and so on.

For NO3, I need a level of 10-20 for the plants, so this technique won't work. If you are really serious about levels (and there are lots from what I read in the web), you need to make stock solutions To calibrate your own test. These people make accurate solutions of NO3 (using KNO3) of 10, 20, 30, etc. Every time they do a test, they run the stock solutions with their tank water & compare the samples to get an accurate reading.

I never bothered to do this every time. I did it once to get an idea what 20 would look like (and it is nothing like the chart). The rest of the time I more or less guess. From what I understand, the more expensive tests comes with stock calibration solutions to get accurate readings & the hydroponics people would run the calibration solutions everytime they do a test.