Biological Cycle Interrupted?

[jstand22]

It has become apparent that something interrupted the biological cycle (nitorgen cycle) in my aquarium. I noticed a huge spike in nitrites, telling me that I missed the ammonia spike. No fish have been added, but could this be caused by water changes? I add conditioner to remove chlorine to the watter I add before it goes into the aquarium, could this kill of the bacteria needed for the cycle? Also I put in a new air pump that's pumping ALOT more oxygen into the aquarium than the dinky one before, could all that oxygen helped to form all the NO2? I have not been sucessful in lowering the level (reading 5+mg/L)...I did about a 40% water change, and the next two days did 2 15% changes with no results. Reduced feeding; Tried adding Amquel plus (supposed to remove ammonia, nitrites, nitrates) with no luck.
Please help....My favorite fish already died I don't want to loose any more.

Aquarium is a 46 U.S. gal freshwater - 3 stage rena filstar xp2

 

[dzsigmond217]

That stinks! I'm kinda going through the same thing..but with ammonia right now. I just keep doing massive water changes. I also have a Ph problem tho. Wish I could give you better advice! I would keep doing water changes until someone with some helpful advice replies to your thread!! Good luck!

 

[rdd1952]

I'm not certain what could have caused the spike but you need to do a few large water changes to get the level back down. I would do a 50% WC as soon as possible and then another one in a about 3 hours. Then do smaller ones as needed to keep the nitrite below .25 ppm until the cycle finishes.

You mentioned that you lose your favorite fish. Are you certain that there wasn't another dead fish that may have been missed and left in the tank to decay? That could cause a spike. How did you cycle the tank before adding the fish? What fish do you currently have in the tank? What are your readings for ammonia, nitrate and pH?

 

[jstand22]

I'm not certain what could have caused the spike but you need to do a few large water changes to get the level back down. I would do a 50% WC as soon as possible and then another one in a about 3 hours. Then do smaller ones as needed to keep the nitrite below .25 ppm until the cycle finishes.

You mentioned that you lose your favorite fish. Are you certain that there wasn't another dead fish that may have been missed and left in the tank to decay? That could cause a spike. How did you cycle the tank before adding the fish? What fish do you currently have in the tank? What are your readings for ammonia, nitrate and pH?

When I say that I lost my favorite fish, it's not that he disappeared in the tank, but that I found him stuck to the filter intake and flushed him to fish heaven. It is possible that a feeder fish for my needle nose gar was not eaten, and ended up someplace I couldn't see it. The cycle was completed 5 months ago using 3 mollies. Took about a month if I recall. Ammonia reads very low almost 0 and ph is about 6.5. I have already done a bunch of water changes, but will continue to do so, thanks for the help! If you think of anything else let me know.

 

[rdd1952]

It is possible that happened. Are your nitrates rising any at all?

On a side note, the gar will grow to a foot or more and need a tank that is at least 24" deep from front to back. I believe they also need lots of swimming room.

 

[jstand22]

It is possible that happened. Are your nitrates rising any at all?

On a side note, the gar will grow to a foot or more and need a tank that is at least 24" deep from front to back. I believe they also need lots of swimming room.

Nitrates are about 40mg/L they've been that way since the nitrites spiked...
Ammonia now reads 0, so I'm guessing the cycle somehow restarted...I'm having a tough time lowering the nitrites even after the big and small water changes.

Yeah the gar will be moved to a bigger tank when it starts getting bigger...he's just a little guy right now; I'm saving money for a 75-100US gal.