Another cycling question - I have ammonia and NitrAtes but no NitrItes

[hazyvonne]

Hello everyone! I'm completely new to this hobby, have never had fish before. I've been able to answer most of my newbie questions with some research but this one has got me stumped. I've been simultaneously fishless cycling my 55g main tank and my 10g quarantine tank. For the longest time they were pretty much at the same stage. Now my main tank is done cycling. But something weird started happening in the quarantine tank. When the nitrItes showed up ammonia started going down as expected. Shortly after NitrAtes joined the party. All good. Then one morning I checked and the ammonia hadn't budged - was still at 3 like the day before. The nitrItes were zero. And the NitrAtes were at 35-ish. It stayed like that for almost a week. Then the ammonia slooooowly over a few days went down to zero. Everything else stayed the same (no nitrites, 35-ish nitrates). I dosed ammonia back up to 3. That was about 4 days ago. And all this time I'm at 3 ammonia, 0 nitrItes and 35 nitrAtes. This morning the ammonia had gone down to 2-ish, but again 0 nitrItes and 35 nitrAtes.
Anybody experienced that before? What do I do? Kind of a bummer to have the main tank ready but the quarantine tank dragging behind...

 

[Myraan]

It sounds like the cycle restarted for some reason in the small tank. Personally I think washing a filter in tap-water killing the BB is a myth.... but did you do that and thus proved me wrong?

I suppose you are good to go adding fish to main tank either way, but I assume you wanting to do it gradually if you are cycling a quarantine tank (the first addition of fish do not need to be quarantined).... you are already doing better than me or many by even thinking about quarantine.

You could try dividing the media in the two filters between the two and then check how both will cope with ammonia.

Maybe the display tank is not actually cycled with beneficial bacteria - but you have plants that have just started growing? (Plants that survive ammonia, will love to eat the ammonia)

 

[hazyvonne]

It sounds like the cycle restarted for some reason in the small tank. Personally I think washing a filter in tap-water killing the BB is a myth.... but did you do that and thus proved me wrong?

I suppose you are good to go adding fish to main tank either way, but I assume you wanting to do it gradually if you are cycling a quarantine tank (the first addition of fish do not need to be quarantined).... you are already doing better than me or many by even thinking about quarantine.

You could try dividing the media in the two filters between the two and then check how both will cope with ammonia.

Maybe the display tank is not actually cycled with beneficial bacteria - but you have plants that have just started growing? (Plants that survive ammonia, will love to eat the ammonia)

You raise some interesting points. I did not wash any filter in any way. I started out by simply dosing with ammonia. When after 5 weeks absolutely nothing had happened I got a bit impatient and dosed both tanks with seachem seed. They both started with nitrites and nitrates after that, like described above, then the quarantine tank started going weird. I did add plants to the display tank. The reason I think that one is done cycling is because for 2 weeks now I dose to about 3ppm ammonia every day and after 24 hours I have 0 ammonia, 0 nitrites and 30 nitrates (have done a 10% water change to get those down a couple of days ago but clearly that was not enough as it barely made a change).

I was thinking maybe I should cut off a piece of the sponge out of the display tank filter and throw it into the quarantine tank, but I don't know if that would do any good at this point.

 

[FF_Member146894]

I think washing a filter in tap-water killing the BB is a myth

where are you getting this from?
city tap water is specifically treated to kill bacteria

 

[Myraan]

I mean I suspect a quick rinse won't decimate the population; I think they are more robust than that.... If the levels of chlorine in tap water was as high as that no-one would ever need to buy bleach or disinfectant, they could just sterilise everything with cold water fresh from the tap (before the chlorine has dissapated)

I'm not suggesting anyone do that of course except when absolutely necessary, and even then do not wash the entire filter in tap-water at same time.

I could easily be wrong, and I accept that the amount of chlorine added probably varies a lot between cities and even more internationally.

 

[coriesinhawaii]

Is the pH the same in both tanks? I’ve heard that the pH being too low can cause the cycle to stall. Could be different if you have decor in your main tank that is absent in the quarantine tank.

 

[hazyvonne]

Is the pH the same in both tanks? I’ve heard that the pH being too low can cause the cycle to stall. Could be different if you have decor in your main tank that is absent in the quarantine tank.

Well, coriesinhawaii was right on the money. In the beginning I measured ph every day but it never changed so I fell out of the habit of checking it. Didn't even think of it anymore. When I checked the PH on Tuesday it was 6 (or below since the test doesn't go any further than that). So since Tuesday I have added just a very small amount of PH-UP a couple times a day (it seems to wear off rather quickly, I'll do a water change on the weekend which should help better), which gets the PH up to about 7-ish. This morning (Thursday) my nitrItes started coming back (only at about 0.5ppm but that's a lot more than the zero it's been on for so long). So it definitely seems to have been a ph issue. Thank you, everyone for your help in figuring this out!