Nitrate testing

[Curtis]

What's the most accurate way to test for how much nitrates a tank has? I've used AP test kit for nitrates and I think it's fairly accurate.

Let me know what you guys think. I'm trying to figure out what's go on with my lochie friends.

Thanks.

[chefkeith]

AP is a good one. It's tough to tell the color difference in the oranges if the Nitrates are 20 to 80. It does a good job of telling you if the Nitrates are below 20 or are too high though.

[Diana]

Ditto, AP is good. If your nitrates are over 20 your tank needs a water change, no matter how much higher it is. You can test again after the water change and maybe you will need to do another water change in a day or so, or else plant more plants.

The dip stick tests are often wrong. There is a high probability of user error here, as the timing to read the nitrate test is very close, only a few seconds off and the test will show too high or two low. If your tank is low (under 20 ppm), it is easy enough to read (even if you miss the timing), but if your tank has too much nitrate how can you tell the difference between dark pink, deep pink and rich pink? You can't. Just do a water change. This test is more like a Safe/Danger and no real idea of how bad the situation might be.

[Curtis]

Are there any tests that give you a better degree of accuracy? If your read my other posts, I'm changing my drip rate on my continuous drip system to try to resolve some issues... so I'm wondering if there is a good way to tell with a better degree of accuracy how much nitrates are in the water.

We could go by TDS/EC but that doesn't completely indicate additional nitrate.

Thanks.

[Diana]

$ = better tests.
The more you spend, the more accurate.

I would stick with the AP as a happy medium: reasonably priced, and accurate enough.

Something like a La Mott or Hatch is probably better, I think this one has reference samples in test tubes for you to compare your test tubes to, not just colors on a card.

[chefkeith]

There are Hanna NO3 photometers. It's a little expensive though.
http://www.drsfostersmith.com/product/p ... atid=15513

There are also various NO3 probes, that are even more expensive.
http://www.fishlab.co.uk/index.php?act= ... roductId=4