Master Test Kit Vs. Test Strip Results

[tmack]

Hi. One of my fellow workers has an established tank at my workplace, and his nitrAte levels have been very high, even after partial water changes. He's been using the Jungle 5 in 1 test strips and his readings using the strips are:

Nitrite approx. 0.25
Nitrate 160 - 200
pH 6.8

When I test with the API Master Test Kit solutions I get (and he also gets after just getting a Master Kit himself):

Nitrite 0
Nitrate 5-10
pH 7.0

(ammonia with both test kits is 0)

Has anyone else seen this kind of huge difference on nitrAtes between the test kit and the strips? As I said he now has a test kit also and gets the same low nitrAte reading that I get with my test kit solutions. I've always considered the test kits to be much more accurate than the strips but I never expected to see this kind of difference! The other readings between the kit and strips are close to each other but the nitrAte difference has me wondering if the strips are any good, or if the test kits are at fault.

Thanks

 

[dizzied]

I would trust the master test kit because test strips are faulty.

Are the two tests using the same unit of measurement?

 

[celaeno]

the api liquid test solutions expire after 3-5 years.

 

[tmack]

Hi. My test kit is only about a month old (replacement) and my work buddies was puchased yesterday. I couldn't see any expiration dates on the bottles, but I'll look again.

Yes - both are ppm (same as mg/liter) measurements.

I guess I'll believe the test kit measurements more than the strips he's been using. Still surprised that the nitrate measurements could be such a magnitude of difference between the two tests.

 

[celaeno]

the manufacture date for the api liquid test solutions are the last 4 digits of the lot no. for example, if the last 4 digits are 0306, then the manufacture date is march 2006.

 

[tmack]

I guess I'll trust the test kit solutions. I was wondering if something could be told from the lot numbers. Nitrate bottle 1 is 10/06 (October 06 manufacture) and bottle 2 is 12/06 (December 06 manufacture). Thanks for the quick reply - excellent information to have!

 

[dizzied]

I should also point out that if the nitrates are beyond what a test strip measures, it can give off a wrong color. This tends to happen to me when I cycle.

 

[tmack]

Were you speaking of the test strip color or the solution test color? If it's the solutions I could always do dilutions of the tank water before testing his tank.

 

[Killi]

I have both strips and liquid but I find the liquid gives more easier to read, and more accurate results.

The results on both are approximately the same

 

[@ombomb]

the api liquid test solutions expire after 3-5 years.

I wouldn't trust a nitrate test that was much more than 6 months old.

 

[celaeno]

the api liquid test solutions expire after 3-5 years.

I wouldn't trust a nitrate test that was much more than 6 months old.

if you don't believe me, e-mail or call api yourself.

 

[tmack]

We just re-tested the tank mentioned at the start of this thread, after a 30% water change yesterday, and with the test kit solutions we got:

Ammonia: 0 (nice clean yellow yellow - not even a hint of green)
Nitrites: 0 (nice sky blue color)
Nitrates: 0 (nice clean yellow color as with the ammonia test)

Are readings this good possible? I would expect to see a small amount of nitrates at least, unless the level is close but not actually zero. I wish I had readings this good on my home tank, but I'm really wondering about the test solutions, even though they are all of October 06 or newer manufacture. I'm tempted to see if I can email API with the test solution lot numbers & see if they can check any retain samples they may have for accuracy, but I thought I'd post here first to see if anyone else gets readings this good.

 

[tmack]

I went ahead & sent an email to API, told them the test differences on nitrates between the test solution & strips & asked if they could test any retains of my lot numbers to be sure they were manufactured correctly. Hard to believe a tank could test that perfectly, and have no ammonia, no nitrites & no nitrates (and the tank is a bit overpopulated with fish, no real plants, biowheel filter). Still interested to hear if anyone else is getting those zero readings in their tests, especially nitrates.

 

[andywg]

the api liquid test solutions expire after 3-5 years.

I wouldn't trust a nitrate test that was much more than 6 months old.

if you don't believe me, e-mail or call api yourself.

I don't trust the API nitrate test at all.

I have had a panic before with my nitrate kit reading all sorts. I tested my large FW tank with two samples at the same time. One came up 0ppm, the other 160ppm. On my reef I thought I had extremely high nitrates. Checked the RO + Salt mix and it was measuring well over 100ppm on that, despite the TDS meter showing the RO at less than 5 and two other brands of test kit showing it a lot lower (like under 10).

I used to rate API, but now find them to be very hit and miss.

 

[tmack]

If the API nitrate test solutions aren't dependable, does anyone else sell test kit solutions that are?