Strange Nitrate readings.

[Chino1130]

Hey folks. I began my fishless cycle of my new 25 gallon tank on Sept 21. The cycling has been going to plan until last night.

Sept-22 -4:00pm
Nitrates > 4ppm
Nitrites = 0
Nitrates - didn't take a reading (probably should have)

Sept 26 - 3:30pm
Ammonia < 1
Nitrites > 5
Nitrates >20/<40

I added more ammonia and got it back up to 4ppm.

Sept 27 - 7:30am
Ammonia = 1
Nitrites > 5 (I'm guessing between 6-8)
Nitrates = 40-80ppm

I added more ammonia and got it to 4-6ppm.

Sept 27 - 9:30pm
Ammonia <.5
Nitrites > 5 (6-8)
Nitrates = 5-10ppm ???

I tested the nitrates again 20 minutes later after getting ammonia back to 4ppm, and got the same reading.

Sept 28 - 6:15am
Ammonia = .5-1ppm
Nitrites > 5
Nitrates = 5-10ppm ...???



I have a few small plants in there with no Co2 (waiting on my diffuser), so I don't think that's it. I'm totally baffled on what could be happening. I've tested the nitrates of my other tank (almost 1.5 years old now) and got the readings I expected, so I don't think I'm getting false readings.

 

[librarygirl]

It could be the live plants. Did you have the higher nitrate readings with the live plants or before you added them? The nitrate test is very tricky and picky. I did it one night like I usually do; it was during the fishless cycle and the night before I had something like 40+ nitrate. I did the test, counted the seconds for shaking the bottle and tube, thought I did it correctly, but nitrate showed at 0. I panicked and redid the test, this time banging the bottles against a table (they have a reagent powder in them, particularly bottle #2) that can get clumped and cause inaccurate readings) and shaking more vigorously and the test came back normal. If it isn't a false test or the live plants I'm not sure what it could be.....

 

[Chino1130]

It could be the live plants. Did you have the higher nitrate readings with the live plants or before you added them? The nitrate test is very tricky and picky. I did it one night like I usually do; it was during the fishless cycle and the night before I had something like 40+ nitrate. I did the test, counted the seconds for shaking the bottle and tube, thought I did it correctly, but nitrate showed at 0. I panicked and redid the test, this time banging the bottles against a table (they have a reagent powder in them, particularly bottle #2) that can get clumped and cause inaccurate readings) and shaking more vigorously and the test came back normal. If it isn't a false test or the live plants I'm not sure what it could be.....

They plants were in the tank minutes after I filled it with water for the first time. I have now done the test 3 times, and I have gotten the same result each time. I shake the bottles very hard, as well as banging them on a table. The plants are very small, I can't imagine them having any kind of significant impact. This is where the plants are at right now.

 

[jeffp]

are you shaking bottle #2 when you do the nitrate test? the solution in that bottle can settle, which will lead to low readings.

 

[Chino1130]

I'm shaking the heck out of it. I have tested the nitrates 3 times now. All three times I get the same result. When I test my other tank, I get a reading of 40.

 

[Chino1130]

So I realized something as soon as I woke up this morning. When I purchased my tank, it came with a bunch of sample bottles; a water clarifier and a liquid plant food. I never used the water clarifier, but I did use the plant food a few times. I used it as instructed. I realized this morning, I haven't added the food in a few days.... right around the same time I noticed a crazy drop in my nitrate levels. Is it possible that there was something in the food that was showing me the high nitrate readings? I hope that is the case. At least that explain why my nitrites are still high and my nitrates are so low. Anyways, I added the food in this morning and will be testing when I get home tonight. The food would have been in there a good twelve hours or so by then.