OK, folks, I have to make a confession. I've stopped doing nitrate tests a long time ago. Some readers may find my reasoning obvious and wonder why I'm rehashing accepted wisdom. Other readers may find this crazy. Well, I have a crazier one for you.
I dont believe the numbers people report on forums from NO3 tests mean anything whatsoever, unless something has gone very wrong and the tank has 20+ nitrates. So I think anyone keeping a healthy reef tank who is doing NO3 tests is probably throwing away money on these tests too.
Here is the thing. In about 5 years of testing water in a series of 6 different tanks, I have never, ever, seen a nitrate level thats different from zero. Salifert tests. Rock solid zeros always, except for during cycling.
Why is that a problem? Doesnt that just mean my tanks are low nutrient? NO. I clean algae off my glass every 3-4 days. There is obviously, unarguably, NO3 in the water.
Even worse, take a look at those color charts. I've compared the kits. Can we stop fooling ourselves? The human eye isnt going to detect a difference between 0 and 5 on Salifert, or any other test I've looked at. A person can look at the chart and subjectively, based on their mood, the weather, and the lighting in the room, decide to mark down one number or another. But lets not kid ourselves. All we're really doing is saying "there is not much NO3 in my tank". We cannot tell the difference between 0 and 5, let alone 0 and 2, with these kits.
Is there a place for NO3 kits? Sure. Two places. Cycling and tanks where something is going wrong. I'd put these test kits right up there with Cu test kits: limited to very specific cases, not useful for daily or weekly testing.
In summary: in my experience NO3 tests appear to tell me nothing about the level of NO3 in my tanks. Still doubt it? I dose my tanks daily with 2 ppm nitrate (final concentration, calculated from mass and volume). And even after those doses, cant see any change in NO3.
I will be curious to hear feedback. Prove me wrong! I like testing and believe in water quality testing but I just do not see any evidence there is value to NO3 testing.
[I should add the caveat here that I have not explored Hanna NO3 tests; in principle a spectrophotometric assay has the ability to detect these low concentrations in an objective and reproducible way]
I dont believe the numbers people report on forums from NO3 tests mean anything whatsoever, unless something has gone very wrong and the tank has 20+ nitrates. So I think anyone keeping a healthy reef tank who is doing NO3 tests is probably throwing away money on these tests too.
Here is the thing. In about 5 years of testing water in a series of 6 different tanks, I have never, ever, seen a nitrate level thats different from zero. Salifert tests. Rock solid zeros always, except for during cycling.
Why is that a problem? Doesnt that just mean my tanks are low nutrient? NO. I clean algae off my glass every 3-4 days. There is obviously, unarguably, NO3 in the water.
Even worse, take a look at those color charts. I've compared the kits. Can we stop fooling ourselves? The human eye isnt going to detect a difference between 0 and 5 on Salifert, or any other test I've looked at. A person can look at the chart and subjectively, based on their mood, the weather, and the lighting in the room, decide to mark down one number or another. But lets not kid ourselves. All we're really doing is saying "there is not much NO3 in my tank". We cannot tell the difference between 0 and 5, let alone 0 and 2, with these kits.
Is there a place for NO3 kits? Sure. Two places. Cycling and tanks where something is going wrong. I'd put these test kits right up there with Cu test kits: limited to very specific cases, not useful for daily or weekly testing.
In summary: in my experience NO3 tests appear to tell me nothing about the level of NO3 in my tanks. Still doubt it? I dose my tanks daily with 2 ppm nitrate (final concentration, calculated from mass and volume). And even after those doses, cant see any change in NO3.
I will be curious to hear feedback. Prove me wrong! I like testing and believe in water quality testing but I just do not see any evidence there is value to NO3 testing.
[I should add the caveat here that I have not explored Hanna NO3 tests; in principle a spectrophotometric assay has the ability to detect these low concentrations in an objective and reproducible way]
