Nitrite Spike

[carpking]

Hi

My tank has been up and running for years now but to my horror I switched the light on this morning to find 3 dead rainbows first thing I did was check amonia and nitrite and found the nitrite to be very high any idea's on why its spiked and how I can bring it I'm just about to do a large water change and media rinse

Thanks in advance

 

[techen]

How often and how much water.

Did you change anything days before or move anything.

The nitrite may just be your filter being out of a cycle due to high amounts of ammonia.

 

[carpking]

I hadn't change a thing, so I did a big water change last night and that has brought it down I will do another tonight to improve again.

I did treat the tank for fin rot one of my seemed a little tatty could this effect the nitrite I didn't think it could???

 

[TwoTankAmin]

Nitrite comes from the ammonia oxidizing bacteria. Something caused your ammonia to bump up which in turn caused nitrites. Depending what you used to treat the fin rot, it may have killed off some of your bacteria. Thus you may have gone through a bit of another cycle and not noticed it during the ammonia phase.