dreamermama
New Member
I purchased the API water test kit and I'm loving all the pretty colors LOL (of course the goal is simple yellow or light blue).
My question is, how much do you hold the test tube up to the card?
The directions say to hold the tube up against the white of the card in a well-lit area. I do hold it up with the light hitting it, but I've noticed, at least with my darker nitrate readings, that the color looks darker with the card behind it and lighter with just the white wall behind it (light shining through). So with nitrates, it is really hard to tell whether between 20-40 ppm and 40-80 ppm. Of course, I find the colors on the Nitrate card very close at those ranges anyway.
Any tips?
Thanks.
My question is, how much do you hold the test tube up to the card?
The directions say to hold the tube up against the white of the card in a well-lit area. I do hold it up with the light hitting it, but I've noticed, at least with my darker nitrate readings, that the color looks darker with the card behind it and lighter with just the white wall behind it (light shining through). So with nitrates, it is really hard to tell whether between 20-40 ppm and 40-80 ppm. Of course, I find the colors on the Nitrate card very close at those ranges anyway.
Any tips?
Thanks.