Nitrate problems

Hmmmm..... Aquarium Water Changes.
Is Dilution - The Solution?
To - Water Pollution?
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Well indeed, in this case it may be!
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. (+5 for the Nitrates already in your Tap water).
Yep.
It really is, THAT quick.
But get this.... the more fish you put in the aquarium? The faster the Nitrate level will build up in there! Oh yes....
It can get vicious, actually.
And is unfortunately the dreaded reality that just about all Cichlid keepers, (Esp. New World) face eventually. You HAVE to stay ahead of those Nitrates (They are Toxins). Striving constantly to keep them down to a relatively safe, 20-30 ppm in your aquarium. Or, your fish will almost inevitably become sick if the levels get too high. They may actually die.
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And, for those of us that wind up with big fish - in too-small tanks? We may end up pushing some serious water in those too-small tanks to keep our Cichlids relatively happy and healthy. I'm talking 80 to 90 percent water changes in some cases - done twice per week!
And for most of us in this hobby, that's just more work than we can sustain to enjoy this thing. :?

A 40 PPM (40Mg/L) measured Nitrate level is going to put some serious stress on aquarium fish. New World Cichlids kept at those levels are at high risk of developing HiH/HLLE.
Beyond that, the problems with municipal supplied sources of tap water, definitely get more complicated....
The UK has set a limit of 50Mg/L on their municipal supplied tap water. That is considered a safe level to shower/bathe in or wash dishes. But, I'm not sure many people drink water right out of the tap in the UK.
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The maximum allowable Nitrate level for U.S. supplied, municipal tap water is 10Mg/L. A study of Nitrate water contamination and it's causes and effects was done by Cornell University in 2020 and posted online in a report.

http://psep.cce.cornell.edu/facts-slide ... grw85.aspx

For our purposes as aquarium-keepers in areas with high Nitrate level tap water... these are the only reasonable solutions that can be done to remove or at least mitigate the Nitrates in the water,

- REMOVAL: Filter the tap water first through a Reverse Osmosis filtration system (A recent C-f member 'Monkeynuts' informed that he was doing just that for his aquarium. Nitrate elimination?). Water reservoir accumulation of the RO filtered water may be the only practical means to utilize this method for aquarium use.
- MITIGATION: Plant the tank heavily with aquatic plants. Stock very lightly with fish. Planted freshwater 'refugiums' are even being utilized more and more with some effectiveness as part of the overall, aquarium filtration system to capture Nitrates out of the aquarium water.
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The environmental problem of ground water Nitrate contamination in the UK is addressed here,

https://consult.environment-agency.gov. ... p-2021.pdf

Kind of grim, actually... and this could be a look at contaminated ground water problems we may soon be facing in the U.S.

DJRansome said:

The lower end has more differentiation between 10 and 20 and higher.

Click to expand...

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?

DJRansome said:

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.

Click to expand...

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.

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.

10: C6600E
20: BC5D22
40: AE1C14
80: AE0E16
160: 870A10

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).