Nitrites in cycled tank

[julielynn47]

This is probably going to sound like a stupid question. But why would nitrites show up in a cycled tank? No ammonia, but nitrites are reading .25

This is in my 10 gallon that I was getting ready to add shrimp too next week. I know I can't add shrimp with nitrites.

Nitrites have read 0 for well over a week now. I decided to check it tonight, I don't know why, but I just thought I should, and the ammonia is 0 but the nitrites are back. So I am guessing the tank is not fully cycled. If it is indeed cycled why the nitrites? I am a little confused here.

 

[StevenF]

When fish product urea that degrades to ammonia. Then bacteria convert it to nitrite. And then finally bacteria convert it to nitrate. This happens in a cycled tank every day. It is no different than the cycle in a uncycled tank.

The only real difference between a cycled tank and an unicycle tank is that the one has a lot of bacteria while the other doesn't. So in an uncycled tank the conversion of ammonia to nitrate occurs slowly. In the cycled tank it occurs quickly. As a result of the faster processing of waist is that there is less ammonia and nitrite in the aquarium to register in a test.

With equipment sensitive enough you will always read Ammonia , and nitrite in a cycled tank. but always at levels well below what is considered dangerous.

so why do your have nitrites now? it could mean something in the has changed. Or you might have made and error in your water test. Another possibility is that there is now too much bacteria for the amount of available food ( ammonia). you were feeding the bacteria ammonia earlier but now that your tank is "ready" you have stopped and the food supply has dropped and some of the bacteria may have died.

In a newly cycled aquarium it is often recommended to do a water change just before adding fish. And then after that you should monitor more frequently and if necessary do more water changes. The reason for this is that adding fish creates a change and it might take some time for the tank to re-stabilize to the new conditions

 

[julielynn47]

Okay, thanks. I am not adding any shrimp until I know it is cycled. I think I will add ammonia drops this morning and see what happens. Then I will feed it everyday, even though I have not livestock in the tank, to make sure the bacteria stay alive. I did not know that they would die off that quickly. I thought they would live for awhile without ammonia. I guess maybe that was not the case.

I checked the nitrites twice last night to make sure I didn't do something wrong with the test, and I just checked it again this morning, same reading, .25

edited to add... it may have been a mistake, only time will tell me, but I just added the full ammonia dose again. I will see where that takes me. One day....I swear...I will HAVE shrimp in this tank.

I think I will put another bottle of the SafeStart in as well. It may be overkill, but if the bacteria died off, then I just want to boost it again. And I will feed it everyday until I get livestock in the tank

 

[julielynn47]

Okay, so I added the full ammonia dose yesterday. Waited a few hours and checked the ammonia and nitrites. Ammonia at 1.0, Nitrites at .25. Checked again before bed last night and the ammonia was at .50 , nitrites at .25. This morning the ammonia is at .25 and the nitrite is at .50. Obviously I do have some bacteria left in there, but it has been compromised is some sort of way. Nitrates are around 40. Water temp is 78, so that should be good.

What I plan to do today is do a 50% water change, then add another bottle of the SafeStart, and go from there. I probably don't need to add another bottle, that is probably overkill, but I just want the tank cycled. So this is my plan for the tank today.

And like I said, I definitely will "feed" the bacteria daily after it appears cycled again.

I decided against the water change. I mean why? There is nothing in there that the high nitrate will hurt so I am just adding the SafeStart and seeing what happens

 

[julielynn47]

This morning, less than 24 hours after I added the SafeStart, the ammonia reading is 0. The nitrites are reading below the .25 range, but I can't tell exactly what they are as there is nothing lower on the color card than that except 0. So I would say it is almost at 0 for nitrites this morning. I will definitely keep them fed this time. If all goes well then maybe I will be able to get some shrimp by the end of the week.

 

[Byron]

This morning, less than 24 hours after I added the SafeStart, the ammonia reading is 0. The nitrites are reading below the .25 range, but I can't tell exactly what they are as there is nothing lower on the color card than that except 0. So I would say it is almost at 0 for nitrites this morning. I will definitely keep them fed this time. If all goes well then maybe I will be able to get some shrimp by the end of the week.

Nitrifying bacteria will not die off for lack of "food" as quickly as some assume. They go into a sort of hibernation, or suspended state, to use terms that should convey the point. Once they are present, they will not disappear so quickly. The pH and temperature affect them, but about the only thing that will kill them quickly is drying out.

While I'm here, I will also mention that studies have shown that the nitrite-oxidizing bacteria (Nitrospira sp.) are affected by ammonia concentrations, becoming inhibited and even unable to reproduce, and further becoming dormant. Kim et al. (2006) determined that when ammonia was at 0.7 mg/l (=ppm), the nitrite oxidizing bacteria became 50% less effective, causing a rise in nitrite. This isn't much, less than 1 ppm ammonia.

Byron.

 

[julielynn47]

Well, I cant figure it out. But anyway, this morning the ammonia and nitrites are at 0. I am just going to get something, shrimp, snails or something this coming weekend to put in this tank and let it produce the ammonia the bacteria needs. I am so ready for livestock in this tank.