False high nitrate readings.

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Caincando1

Aquarium Advice Regular
Joined
May 23, 2006
Messages
50
Location
Rochester, MN
I'm hoping some of you can shed some light on my dilemma. A month ago we moved into a rental home with a well. I bought a new water test kit(the stick type) from the LFS and tested my water. The nitrates where almost 40ppm from the tap. So I took a sample and took it to the lfs and they tested it themselves with there own test kit and found the results to be the same. I informed the owner of the house and he took a sample to the county to be tested. The results from the county show 6.5ppm. Myself and the lfs have continued to test the water and we are still showing levels close to 40ppm. When I test it I test it straight from the tap and when I take it to the lfs I put it in a brand new baggy. I've called the county and they couldn't give me any explanation for our high readings. They checked past history of the well it the last test was also brought in by the owner and showed 6.2ppm in 2002. But they have no records later than that and the well has to be 20 plus years old. So we are trying to track down the previous well records.

In the mean time has anyone else ran into a situation like this. I thought I'd ask before I take in a sample myself and pay the county to test it.
 
I thought I'd ask before I take in a sample myself and pay the county to test it.

Take a few minutes and search the web...find an independent lab with a comparable price.

Or at least thats what I'd do....If water quality were my concern,the last party I would pay is the county where the water exists imo.
 
Couple ideas:

1) Presumably the county has a much more accurate test than out hobby grade kits. Our kits are toys in comparison.

You could try diluting the sample with 1 part tap water and 3 parts RO/DI water, so its a more readable color on the test kit, and then multiple the test kit result by 4, just to see how different the reading is. Kind of pointless experiment though since its still dependent on the accuracy of a hobby kit.

2) Maybe the guy diluted the sample himself. Not saying he did, just saying. Perhaps give the county a sample yourself?

In the end, how about growing some Anacharis, Hornwort, or other low-light easy plants? They'll grow fast, and trimming them is an excellent form of nutrient export.

Good luck.
 
its the strips, LFS use liquid reagent test kits, test strips can go bad overnight when exposed to air, they also have an experation date on the bottle, usually on the bottle, they may be old, switch to a liquid reagent test kit and you'll have the most accurate results
 
tropicfishman said:
its the strips, LFS use liquid reagent test kits, test strips can go bad overnight when exposed to air, they also have an experation date on the bottle, usually on the bottle, they may be old, switch to a liquid reagent test kit and you'll have the most accurate results

I have the strips but the lfs has the liquid reagent test kit and they are both reading the same. :( :( It just seems odd that both tests are the same and neither match the countys results. I should know more Wed. when I get the results from the independent lab.
 
Okay, I'm bringing this back up. I had the water tested by an independant testing lab. The nitrates where 5.81 which is lower than the 6.5 that the county tested at. So this means my tap water is good. But it doesn't explain why I'm consitantly testing the nitrates at 30-40 right out of the tap. There has to be something in the water that is tripping off the nitrate test of these aquarium test kits.

UUGGGG!!!!!
 
Could be a bad test kit. The bottles could have been cross contaminated. Could just be and from the posts we get through here, it seems feasible to me that the hobby grade nitrate kits are just not worth the effort to use. JMO
 
Have you considered switching test kit brands? I use the Aquarium Pharmaceuticals liquid test and have found it to be pretty good. The liquid tests are supposed to be much more accurate than the paper strips. They're much cheaper than the dip strips, I just saw some at Drs. Foster and Smith for $5.79. Here's a link:

http://www.drsfostersmith.com/Produ...ll&Ntx=mode+matchallpartial&Np=1&N=2004&Nty=1

Good luck figuring it out.
 
It's been tested with different kits including brand new reagent kits that the lfs uses on a daily basis. I'm going to buy a new nitrate kit and test it again. If it's still the same, I'm going to just start a fishless cycle and use the current readings as a base line. The amonia and nitrate are all at zero and everything else looks fine.
 
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