Nitrites Will They Ever Go Down?

[DanielG]

hi my fishless cycle is like this

ammonia dopping from 4ppm to 0ppm over night
nitrates going up
nitrite off the scale

i did a 50% water change today and added some more plants, and then retested:

nitrites still of the scale!!!!!

nitrites must be so high its unbelievable i just cant see them ever dropping

 

[dthoffsett]

You don't need to do water changes while doing a fishless cycle, in fact it can slow the cycle down. Nitrite generally takes twice as long (or longer) to come down than the ammonia did, the bacteria that breaks down nitrite multiplys slower than the bacteria for ammonia. Just stay patient, it will happen.

 

[DanielG]

i only did a water change so it was easier to plant my new plants

 

[Gremily]

How long have you been cycling for?

 

[DanielG]

about 3 weeks

 

[Gremily]

I really don't think there's anything to worry about yet, just keep taking readings and it will eventually go down. Try to avoid water changes aswell.

 

[rdd1952]

If your around 3 weeks, you are fine. The reason nitrite goes up and stays up for so long is twofold. First, the bacteria that process nitrite develop and multiply slower than those that process ammonia. Second and probably most important is the amount of nitrite you are adding to the tank (via processed ammonia). Remember you added ammonia once and waited for it to drop. With nitrite, you are basically adding it every time the ammonia drops to zero (probably twice a day) so you are probably adding 6 to 8 ppm of nitrite every day. I would not be surprised if the nitrites reach 50ppm or higher during the later stages of a fishless cycle.

 

[Straydum]

yeah just let it cycle. it'd drop soon.