nitrite question

[esoxlucius]

My current stock levels and feeding regime mean my nitrates usually get up to about 20ppm every 6 days which is when i do my maintainance/water change. At this time my ph is 6.4, my ammonia is 0ppm and my nitrite is 0ppm. Today is my 5th day in my cycle so my maintainance is due tomorrow. However, i've just tested my parameters now, everything is as expected but my nitrite for some reason is not the very light blue denoting 0ppm but somewhere inbetween the light blue and the lightest purple colour (between 0ppm and 0.25ppm....and yes i've tested it three times to be certain....and it's the same each time). I was taken aback because this hasn't happened before. Do i do my maintainance now as a matter of urgency or would it be ok to leave until my scheduled day which is tomorrow? More concerning, what has caused this?

 

[pops]

sounds like you had a little bump in your bio filter, while nitrite is very toxic, .25 is not that bad. if it happens again next week, I would be looking for the cause.

 

[esoxlucius]

sounds like you had a little bump in your bio filter, while nitrite is very toxic, .25 is not that bad. if it happens again next week, I would be looking for the cause.

The ammonia is the first part of the cycle is it not? If my ammonia had gone up a tad i could understand that but why is my nitrite wobbling yet my ammonia is 0ppm or am i not understanding the science of the cycle properly?

 

[Angelphish]

The bacteria that eats nitrite grows slower than the one that produces it, so you could just have more ammonia.

 

[Pomatomus]

Did you just feed the tank? That could cause a temporary spike. Do you think you have any denitrification going on in the tank? A small amount of nitrite could be a byproduct. Did you pH fall below 6? That can impact your biofiltration.

As long as you have some chloride ions present in your water (e.g. from adding salt) then I wouldn't worry too much. Even a few ppm will keep most of the nitrite from being taken up at the gills. If your fish look like they are struggling to get oxygen then you know you have a problem for sure, as nitrite prevents hemoglobin from carrying oxygen. This condition (brown blood disease) will leave your fish looking like they are suffocating.

 

[esoxlucius]

Did you just feed the tank? That could cause a temporary spike. Do you think you have any denitrification going on in the tank? A small amount of nitrite could be a byproduct. Did you pH fall below 6? That can impact your biofiltration.

As long as you have some chloride ions present in your water (e.g. from adding salt) then I wouldn't worry too much. Even a few ppm will keep most of the nitrite from being taken up at the gills. If your fish look like they are struggling to get oxygen then you know you have a problem for sure, as nitrite prevents hemoglobin from carrying oxygen. This condition (brown blood disease) will leave your fish looking like they are suffocating.

I feed first thing in the morning, once daily. I used to have a problem with my ph going as low as 6 but since i added a bag of crushed coral months ago my ph always hovers around 6.2-6.4, it may get as high as 6.8 after a water change. Fish look fine, no unusual behaviour, i use my dennisons as a guide as they'd be the first to suffer if absorption of oxygen was a problem. One thing i did find about an hour ago was a biggish piece of uneaten cucumber hidden in one of my pvc pipes that my clowns hide in. I usually remove uneaten food rapidly but i overlooked this with it being out of sight. It's been in there since Thursday, could this be the culprit, would this cause a slight nitrite spike?

 

[duanes]

How well to you clean the cuvette you use between testing?
If you do a test, and basically let the vial sit until the next week, there could be a residual buildup. When I worked as a chemist, after each test we would rinse our cuvettes at least 3 times with DI water to remove any residual, then acid wash all glassware at the end of the day.
I wouldn't expect acid wash. But it is always a good idea to purchase a gallon of DI water from the grocery store and rinse 3 times after each test, that way there is no residual to give noise ( a false positive) for any chem, be it ammonia, nitrite, or nitrate.

 

[esoxlucius]

How well to you clean the cuvette you use between testing?
If you do a test, and basically let the vial sit until the next week, there could be a residual buildup. When I worked as a chemist, after each test we would rinse our cuvettes at least 3 times with DI water to remove any residual, then acid wash all glassware at the end of the day.
I wouldn't expect acid wash. But it is always a good idea to purchase a gallon of DI water from the grocery store and rinse 3 times after each test, that way there is no residual to give noise ( a false positive) for any chem, be it ammonia, nitrite, or nitrate.

My vials get a pretty good rinse after testing in hot water. Then before my next test they'll get another hot water rinse before a good dunking in tank water. Then i'll do my actual test. I don't think i'm getting any contamination from previous tests.

 

[duanes]

If your water company uses chloramine as a disinfectant, a rinse in hot water is not enough.
Because DI water is devoid of any chemical content, it has the capacity to pull residual from microscopic fissures in the vial. Tap water doesn't. All water is not just water, whether hot, or not, especially when dealing with concentrations on the ppm range.