Nitrite in established tank

[kevino]

Why would I see a sudden appearance in Nitrite in an established (10 month) tank? No Ammonia was detected before the spike. The only thing I did was wash out the wet dry filter sponges and media. Could I have killed off some bacteria in the sponge?

It has lingered around 0.5 for a week, and I have confirmed it via 3 test kits. Did a 20% water change but the Nitrite is still there.

[jeremism30]

First of all I'm not an expert, but yes it's my understanding that if there is not enough bacteria your nitrite level will climb. I am not aware of any other reason that it would rise.

Do you have any live rock and live sand in there?

[jjharrisx4]

The cleaning sounds like the culprit. Have you had any deaths in the tank? snail, hermit, anything? Do you feed any large items? Maybe a rotting corpse is to blame.

[reefinready]

it sounds like the cleaning did that. the bacteria cleaned is what is going to convert the nitrite to nitrate. doing a water change is not going to help to much it might even slow the process. i would simply keep an eye on your fish and proceed like normal until your bacteria grows.

[drscheck]

Most likely the cleaning, but as the others have mentioned. if your bacteria colonies are not large enough and you have a death in the tank, the ammonia may be metabolized, yet the bacteria cannot yet handle the nitrite that quickly.

[DgenR8]

I would be looking for something dead....

[kevino]

DgenR8,
nothing dead... Just the sponge that I rinsed out in the last maintenance. I even did the rinse in RO water. Checked the RO water too, not any Nitrite (or Ammonia)
I'll do a water check tomorrow.
-Kevino