Will 5ppm+ nitrites stall a cycle? Or does it not matter?

[WalkerLoves_TheOcean]

Hey everyone.

I am getting fish this weekend, and I am trying to finish the cycle. Right now, I have 0ppm ammonia, with 5ppm+ nitrites, and around 50ppm nitrates. I have added a couple droos of ammonia every couple of days, but about 2 weeks back I added a full dose (2ppm), and then about a week ago, I added half a dose, (1ppm). Like I said, I have added a couple drops of ammonia here and there, but not much. I would like to add a full dose today, so that way once it goes down, I can get fish, but I don't know if I should with over 5ppm nitrites. I know that it is not relevant to SW, but on the bottle, it says do not add more if ammonia or nitrites exceed 2ppm, which I am way last for nitrites. The bottle isn't for just SW, it is also for FW, so does it not matter for me, and can I add a full dose?

 

[Spare time]

Nope. You are fine. You also don't need to add more ammonia.

You can add fish, but I'd do a water change first.

 

[Spare time]

Out of curiosity which product did you use?

 

[nereefpat]

Quit adding ammonia.

 

[WalkerLoves_TheOcean]

Out of curiosity which product did you use?

Dr. Tims

 

[WalkerLoves_TheOcean]

Quit adding ammonia.

It's a 15g tank, and I will add 3 fish at absolute max, so I can stop?

 

[Red_Beard]

Yeah, stop adding ammonia. The ammonia front loads the bacteria with something to eat in absence of fish and gives it to them in abundance so they multiply to cover all the available surfaces. Once you get them spread out and seeded (usually after the first 2 doses or so) you can quit dosing more and once you see them able to process the ammonia *slowly add fish/ bioload.

 

[nereefpat]

It's a 15g tank, and I will add 3 fish at absolute max, so I can stop?

You just do it once to start the cycle. Then wait until the ammonia test reads zero. Then you are safe for fish. You can wait until nitrite tests zero if you want to be patient, but it's arguably not not needed to wait that long.

 

[taricha]

As others have said, you don't need to add ammonia....(but also, warnings about too much NO2 stopping a cycle don't seem to pan out in practice.)
I cycled a tank that had 40ppm ammonia in it by adding hobby nitrifier products. They took ammonia down to zero. The nitrite was so high that even a 1/10 dilution broke the NO2 test and it turned grey (a color it should never turn). I imagine the nitrite was over 100ppm at that point. Ammonia was still processed all the way to zero.
Not all products are the same bacteria, and some may be more sensitive - but the generalization that ammonia or nitrites over 5ppm will shut down nitrifiers doesn't seem to be widely applicable.

 

[WalkerLoves_TheOcean]

As others have said, you don't need to add ammonia....(but also, warnings about too much NO2 stopping a cycle don't seem to pan out in practice.)
I cycled a tank that had 40ppm ammonia in it by adding hobby nitrifier products. They took ammonia down to zero. The nitrite was so high that even a 1/10 dilution broke the NO2 test and it turned grey (a color it should never turn). I imagine the nitrite was over 100ppm at that point. Ammonia was still processed all the way to zero.
Not all products are the same bacteria, and some may be more sensitive - but the generalization that ammonia or nitrites over 5ppm will shut down nitrifiers doesn't seem to be widely applicable.

Okay, I didn't know that, thanks!

 

[Cell]

Nitrites are not harmful to marine fish at the levels we see. The presence of nitrites will however artificially inflate your nitrate test so until they go down, no real point in testing nitrate.