Nitrate Levels

[unknowntbeast]

My tank is processing the ammonia and nitrite at a good rate, and levels for both are at 0 ppm. But at what level does nitrate become deadly? Yes, I know weekly water changes will keep it down, but I want to have a warning level to say "Hey! You need to do a water change!"

 

[mattlee]

with 30% weekly changes my water never goes above 20ppm and it comes from the tap at 10ppm so i will never get it lower than 10 without fully planting the tank to reduce the levels. the lower the level the better but i wouldnt want mine to rise above 60ppm, but as i said it never really goes above 20.
i may be wrong here but i think if its kept below 100ppm then its not too much of a problem, i remember someone on here saying theirs comes from the tap at 40ppm........
just keep doing regular water changes and using a test kit you will soon know where your levels are at and how much water to change to keep it at the desired levels.

 

[waterdrop]

Right, agree with mattlee. There is no magic number for nitrate(NO3), for a couple of reasons:

Probably 15 or 20ppm *above* whatever your tap water nitrate(NO3) reading is would be a reasonable warning level to set for yourself. So if you had no nitrates in the tap, 15 or 20ppm would be this trigger point. If you had 40ppm NO3 from tap then it'd be 55 or 60ppm. So the number is not the same for different people because their tap nitrate is not necessarily the same.

The other thing to understand is that people have a hard time setting some number to begin with because there are contrasting types of information to know about the topic. Species vary a lot in their tolerance of this substance. Some species are not bothered by 400ppm nitrate and some catfish have been reported as being ok in 1000ppm levels. In radical constrast to that, I've read some stories of GBRs (German Blue Rams) liking the water to be really pristine with NO3 levels below 15ppm being desirable for them.

In most cases its not hard to keep your NO3 below the "20ppm above tap level" if you have established good mainenance habits.

~~waterdrop~~

 

[rebrn]

that is great information waterdrop. I always thought you wanted your levels below 50ppm. Everything I have read thus far gives 50 as the "magic" cutoff number. As mentioned before if you are keeping up with the water changes then you should be ok regardless.

 

[Mikaila31]

Last time I checked my tap comes out at 20ppm. Tanks tested 30-40ppm, I haven't tested in a really long time though. I ignore nitrate, IMO its not important with most fish. I glance at our yearly well water tests to see what nitrate is coming in as. The lab tests are much more accurate. To me the API color chart looks the same for everything above 20ppm. As waterdrop said as long as your tank isn't getting way higher than you tap, your fine IMO.

I've never actually seen a nitrate test reading of zero .

 

[OldMan47]

I keep my nitrates fairly low, but there is some evidence that certain fish can go well into the hundreds of ppm with no harm.

 

[waterdrop]

Last time I checked my tap comes out at 20ppm. Tanks tested 30-40ppm, I haven't tested in a really long time though. I ignore nitrate, IMO its not important with most fish. I glance at our yearly well water tests to see what nitrate is coming in as. The lab tests are much more accurate. To me the API color chart looks the same for everything above 20ppm. As waterdrop said as long as your tank isn't getting way higher than you tap, your fine IMO.

I've never actually seen a nitrate test reading of zero .

Interesting. I've seen pretty good matches to all the different colors on the API nitrate color test chart. It was kind of fun during fishless cycling to see a good match that you'd not seen before. I get to see a perfect zero for nitrate when I test my tap water.

One of the tests I don't have is GH (I only have KH) and I'm curious now to try that. There was an interesting article in the last AGA journal where I believe the author claimed that things were quite bad for plants, at least some plants, in water with less than 3 degrees of GH. Its not a cure-all for not enough CO2 but its still something of interest.

(sorry, that was off-topic)

~~waterdrop~~

 

[OldMan47]

Very low mineral content could indeed make it more difficult for plants to get all of the traces they need from your tap water. Plants can and do grow in very low mineral content water, but not all plants will prosper there.

 

[aaronnorth]

Last time I checked my tap comes out at 20ppm. Tanks tested 30-40ppm, I haven't tested in a really long time though. I ignore nitrate, IMO its not important with most fish. I glance at our yearly well water tests to see what nitrate is coming in as. The lab tests are much more accurate. To me the API color chart looks the same for everything above 20ppm. As waterdrop said as long as your tank isn't getting way higher than you tap, your fine IMO.

I've never actually seen a nitrate test reading of zero .

Interesting. I've seen pretty good matches to all the different colors on the API nitrate color test chart. It was kind of fun during fishless cycling to see a good match that you'd not seen before. I get to see a perfect zero for nitrate when I test my tap water.

One of the tests I don't have is GH (I only have KH) and I'm curious now to try that. There was an interesting article in the last AGA journal where I believe the author claimed that things were quite bad for plants, at least some plants, in water with less than 3 degrees of GH. Its not a cure-all for not enough CO2 but its still something of interest.

(sorry, that was off-topic)

~~waterdrop~~

Well Magnesium is important for photosynthesis & protein synthesis which is why it is reccomended you keep it raised above 3dGH.
Thanks, Aaron