I would do daily water changes, increasing the amount each time until I was changing almost all of the water at once.
No reason to double the amount of Prime.
No reason to double the amount of Prime.
In theory, yes. But how do you "measure" whether you have 40 ppm or 80 ppm nitrates (or anywhere thereabouts or in between)? This has been a thorn in my side for decades. How do you discern if that red color in your test tube is 80, 90, or 100 ppm nitrates? On the lower end, how do you know whether you have 10 ppm, 20 ppm, or 30 ppm nitrates? Seriously. How can you tell?... It's pretty simple, actually. In your case of the measured 80 ppm Nitrates in your aquarium? If you had immediately conducted a 50% water change after that measurement? You would have then measured a 40 ppm Nitrate level in the tank. ...
Assuming you're talking about the API Freshwater Master Test Kit, there is no differentiation between the 10ppm color square and the 20ppm color square. (That's how every API nitrate kit I've ever owned has been -- and I've owned many of them.) But even where there is differentiation (e.g., between the 5 ppm and 10 ppm color squares, and between 20 ppm and 40 ppm color squares) the difference is so subtle that it is negated by the problem of trying to compare a translucent color (the liquid) with an opaque color (the test card). Translucent colors and solid colors simply are not comparable. Period. Sure, you can guesstimate it. But in situations like the original post above, guesstimating doesn't help. Again, how do you "measure" whether you have 40 ppm or 80 ppm nitrates?The lower end has more differentiation between 10 and 20 and higher.
I disagree. I do make my test readings against the white part of the card and in direct sunlight whenever possible. It doesn't help. The 10ppm color square and the 20ppm color square are still identical in color, even in sunlight. Likewise, the 40ppm color square and the 80ppm color square are still identical in color, even in sunlight. Plus, the need to compare a translucent color to an opaque color is still problematic, even in sunlight.It helps to take the tube and card into sunlight and roll the tube across the card so you are looking through the liquid. With the white spaces in between, it is easier to pick the closest match.
For the API Freshwater Master Test Kit, I maintain that there is no gradation at all, subtle or otherwise, between:For me, it IS simple. So, if you're not sure of the actual color? Then,
GET A WOMAN TO LOOK AT IT.
In my dotage I've discovered some pretty amazing things, yes. One of which is that my wife or either of my daughters has MUCH better color vision than I do. Shades and subtle gradations of color are seemingly obvious to them. (As a tradeoff, I also think the wee lasses are almost half-blind at night).
OK, sure. On a similar note, dogs can hear sounds and smell scents that we can't. Unfortunately, color gradations that are too subtle for human observation are of no use to me. The question is are you able to see the difference between 10 & 20 and 40 & 80 with your naked eyes? The few people I have surveyed cannot discern any difference. I'll start carrying the test card with me at all times and ask every person I interact with. Stay tuned for results.Out of morbid curiosity, I dropped the API test kit color chart into an art program so I could grab the hex color codes for nitrate 10, 20, 40, 80, and 160 ppm.
Based off just the hex codes you can see they are all different, however the margin of difference between 40 & 80 is ridiculously slight.
If you're curious enough Here's a link to a hex color chart where you can type in the codes above! You'll put it in where you see #FFFFFF (pure white default).
If inclined you could do the same with readings on a glass tube. Just take a picture of it on a white background and drop it in an art program to color drop. Paint works on a computer you'd just have three numbers vs. hex code, or I use autodesk sketchbook on my phone (it's free).