Nitrates Too High to Register...

[timmay42]

I'm using a colourimetric method for determining nitrates (it's a basic Aquarium Pharma. test kit), but the nitrate levels are just too high for me to get an accurate reading.

I understand there is a means by which you can perform a dilution of your sample in order to zero in on a more accurate measure of your nitrates. I've tried searching for this on forums and in Google, but have come up empty.

Does anyone know of a website that spells out the steps in order to find nitrate levels that are too high for a colourimetric sampling kit to find?

Thanks so much!

-Tim

 

[linderaberry]

Dilute your sample with an equal volume of distilled water. Whatever reading you get, times 2, is what your real level is.

 

[Old Man Of The Sea]

linderaberry, I believe that nitrates can be even higher then that for I known people to have their nitrate levels in the hundreds which I cannot understand why other then those who might over stock or over feed their tanks.

Tim, what size tank is this and number of fish it has and how long has the tank been established for?

Like even in my younger days I had nitrates higher then 300 PPM, yes I did.

Also Tim, how often you are doing your water changes and are you using RO water for this? For the thing is Tim, it isn`t as important to learn of the nitrate level which you have in this tank, but rather that you begin in reducing its levels.

 

[Anonymous]

I found this method by googling at this website: http://www.nitrate.com/faq3.htm

Seems like it would work.

3.4 Q: My sample has more color (higher absorbance) than the highest standard

3.4 A: Your sample has too much nitrate and must be diluted and reanalyzed. SOLUTION: Dilute the sample with nitrate-free deionized water 1:4 (five-fold dilution) and 1:9 (ten-fold dilution) and analyze the nitrate again. If the sample is still off the standard curve (ie. higher in absorbance than the highest standard), then you will have to dilute it more, like 50- or 100-fold.

Tim, what size tank is this and number of fish it has and how long has the tank been established for?

Like even in my younger days I had nitrates higher then 300 PPM, yes I did.

What the Old Man said :lol: I'd worry about how you'd get nitrates that high and work that angle as well.

FWIW, another possibility to consider is how old the test kit is, and if it could be inaccurate.