Cycle Stuck In Nitrite Stage

[jesnon]

Hi everyone,
 
I'm brand new to fish keeping and have been doing a fishless cycle for 8 weeks now on my 23l fluval edge but my tank still seems to be struggling to build up nitrite eating bacteria and it's starting to drive me slightly mad! I've been cycling at 30*c, my Ph is 8.2 and hasn't moved since the beginning of the cycle and I have very hard water. I thought I was almost there with my cycle a couple of weeks ago after my nitrites being off the scale for a long period of time nitrites were finally dropping to 0ppm, but suddenly nitrites reappeared again and it seemed like my nitrite eaters had mysteriously died off. 
 
Over the past week my tank has gone back to processing nitrites from small amounts of ammonia, but I've upped my dose of ammonia and now my nitrites have gone back off the scale. I'm not sure what I'm doing wrong, it just seems to be taking much longer than it should be?

My ammonia is quite weak, it takes around 2.2ml to get to a dose of 4ppm ammonia. I was dosing 0.5ml ammonia and my tank was processing it to 0 ammonia and nitrites within 24 hours.
 
Last night I dosed 1ml ammonia and this morning (12 hours later) my readings are:
 
Ammonia 0ppm
Nitrite 5+ppm
Nitrate between 40 - 80ppm
 
Any advice!?

 

[Welshweeks]

I personally would try to achieve an ammonia level of no more than 2.0ppm. Have you done any water changes? I'm currently cycling a 40L tank and added mature media, my nitrites have been stuck at 5.0ppm+ for several weeks which is strange considering I added mature media from my main tank and the ammonia started to reduce pretty rapidly. I did a water change on day 13 and another one yesterday on day 25 (an 80% water change) and my nitrites are coming down at last, hopefully this trend will continue.
 
Try a large water change? I'm sure someone with far more experience than me will come along with more advice soon! 

 

[jesnon]

Hmm that does seem strange! I guess these nitrite eating bacteria are tricky things. My ammonia reduced pretty rapidly when I started cycling, it's just the nitrites I've been having problems with the whole time! I've done quite a lot of large water changes through the whole cycling process because my nitrites frequently went off the scale and I was advised that too high nitrite levels could slow down the cycle. Unfortunately it didn't seem to make much difference, or only did so for a couple of days before nitrites were creeping back up again. I haven't done a water change for the last week or so, perhaps I should do another water change and see if that kick starts things again! 

 

[mishmash]

I would be inclined to give your filter a kick start and ask your LFS if you can put a small media bag of bio media into their filter system.  It will pick up a nice load of bacteria in no time.  Bring it home in a small container with their water too.  Rinse it in the water you have in the container (not tap water) and add to your filter.  Hey Presto, the cycling gets a kick up the ass.

 

[cpwebsite]

To me, it seems like your cycle was almost done a couple of weeks ago as you said, going back to 0, and then it suddenly appeared again. Do you know if anything happened during that time, like you put in too much ammonia or something like that, because I'm guessing something happened then that either killed your bacteria or gave them too much to handle.

 

[jesnon]

Thanks for your replies. Unfortunately I'm not really sure what happened to kill off all my nitrite eaters, the Ph was fine, temp was fine and I can't think of anything special that happened. 
 
In good news my nitrite eaters are now eating all all the nitrite produced from 1ppm of ammonia within 24 hours. I'm taking it slowly and hoping that soon it'll be within 12 hours! I'll start increasing the dose tomorrow if things are still going well. Fingers crossed to being nearly there and getting some fish soon enough!