[AquaticLife] Question about Nitrate Level
Since your nitrates were only 10ppm and you did a 25% PWC with 0ppm nitrate tap water, it would have only lowered the nitrate in the tank to 7.5ppm which might still show up in the color range for the 10ppm. Since the API test kit has the color codes in increments of 5ppm for the nitrate test, I would imagine that the color difference would be minimal.
Last, but not least, the colors on the API nitrate test kit are part of the spectrum that many people find difficult due to common color blindness that affects up to 25% of adults.. especially men.
Here’s a couple of free online color blindness testing sites if you want to check your own eyes. http://colorvisiontesting.com/
http://www.toledo-bend.com/colorblind/Ishihara.html
Lenny Vasbinder Fish Blog - http://GoldLenny.blogspot.com
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