Is it possible to sabotage a nitrate test?

[AznMexAggie]

I'm wasn't sure which topic this should go under but I had a question regarding the validy of a nitrate test.

My tank has been set up since June, I do weekly 10% water changes and I've yet to experience any fish deaths or any problems. I normally test my water weekly, and it always shows ammonia = 0 nitrite = 0 and nitrate about 10. I work at the local fish store and took my water into work to test it there. I used the API test kits and everything looked fine: nitrate = 10. After about an hour I went back to where my vials were and everything looked exactly the same. Then one of the new employees who is an arrogant freshwater fish "specialist" tells me that's perfect water - you must be starting out a new tank and I told him it had been set up since June. Then he goes back to the fish cart where my vials were and about 15 minutes later I go back there and my nitrates are showing at 160ppm. Then he "instructs" me on how to "properly" test my water (shake the vial for 1 min 30 seconds, remember that there are two bottles for the nitrate test, etc) which I am already aware of and have been doing for the last year and a half (although there is no need to shake the vial for that long - I'm sure with just a 30 sec shake, the chemicals will reach equilibrium even after an hour's time, right?). Then he tells my boss that "obviously I need to rethink my setup and maintenance strategies" and basically tries to make himself look like the know-it-all.

Basically, what I'm asking is if it is possible to sabotage a nitrate test. Would adding extra drops of bottle 2 into my water sample cause my nitrates to read much higher than they actually are? Or are there other ways to cause the nitrates to read higher than they are?

Any insight would be appreciated. Thanks!

[blue_eyes53813]

If the test was sitting for a period of time , it will get darker and darker.. I noticed that once as well... There is a time on the directions to get the reading from the vials.. I think it is 5 minutes.. That would be the correct reading. As it sits it will get darker...

[Dentoid]

I agree with the above, it does get darker as it sits. I once left my nitrate vial over night (forgot) and the nitrate reading was 160 when it first read 20. The best reading for most test kits is 5 minutes after agitation. However, my nitrate tetst kit (Aquarium Pharmaceuticals) instructions are to shake the 2nd bottle for 30 sec before adding the drops then shake the vial after both have been added for 1 minute. this seems like an eternity but is necessary to properly blend. Infact I tried it both ways and got different readings, another thing you can do is run two different tests, say, Aquarium Pharm. and Salifert and compare your readings. The Salifert test uses powders instead of liquids and doesn't require as much agitation.-Scott

[Cougra]

There are many ways to "sabotage" a reading, adding more chemicals can do it as well as adding some water with high nitrates, or leaving the water sample too long or adding other chemicals to the water etc. Also contaminated vials can cause false readings as well.

If you want to set the record straight you'll need to start a new test with water from the tank really. In the mean time you'll need to explain that the test was done a while ago.

Don't worry about the know-it-all employee, eventually he'll get on everyones nurves and people will see through his act, or he'll hamg himself with his own tongue! You're best bet is to just give good consistant advice or admit if you don't know something. However, in the future, I would recommend that you don't leave water sitting around in the vials for any period of time. It's good practice to clean your instruments before (in case something happened to it while it was sitting around) and after (to ensure that there is minimal amounts of residue in the vial) each use. At work it'll make you look more professional when you do water tests for other people and I'll guarentee that gets noticed (only two LFS employees that I know of keep the test equipment clean and as a result they are always the ones that regulars go to for good test results)

[lcstorc]

I agree with both of the above. Follow the instructions exactly on whatever kit you are using. The AP tests do require specific amounts of agitation time and I have gotten false readings by not following the directions.
Also do not worry about mr know it all. Eventually the owner or manager will see through the act and take appropriate action.
Best of luck.

[AznMexAggie]

Thanks, guys. I retested my water with a Hagen Nutrafin test kit and my nitrates read at 10 ppm.

Another co-worker also informed me that he witnessed the know-it-all putting extra drops into one of my vials. I just can't believe that he would stoop so low just to make himself look better.

[lcstorc]

Well being a firm believer in karma I would not worry to much. You get from life what you give and someday it will come back to haunt him.

[Dentoid]

Lynn-take a bow! -Scott

[fishhead]

What a jerk! Unbelievale..hmmph

[Gibeon]

Would it be frowned upon at your place of work to kick him in the nads?

-Gib
(Who's having a bad day...)

[prow]

i think every place of work has those type people in the mix. i usually challenge them and ask why would you do that. dont get all emotional just ask in a matter of fact way. keep your mind and out wit him when he starts doing those knee jerk reactions to your challenge. be willing to go straight to the owner with your issues and do it if needed. tampering with customers tests or the stores tanks is something the owner, i am sure, would like to know. dont get caught up in tit for tat thing, right now your 100% in the right. playing the tit for tat or keeping hostlity on the quite side will only help him make you look bad. or just forget about it, if you can, but remember you dont have to put up with it, its your call.

[kyle1284]

same thing happened to my PH test... tested 8.1 but then came out 8.5 the next morning

[lcstorc]

Kyle, not sure what your timing was on the ph, but it is generally lowest right before lights on. Then goes up as the lights are on for a significant amount of time.

[sasquatch]

AZnMexAggie, Welcome to RS! nice work buddies you got huh.Hope your time spent improves.Steve

[kyle1284]

Originally Posted by lcstorc

Kyle, not sure what your timing was on the ph, but it is generally lowest right before lights on. Then goes up as the lights are on for a significant amount of time.

i was talking about a PH test that was left in the tube overnight when i woke up in the morning it read 8.5