New Tank - Nitrite to Nitrate Stalled?

[talipini]

Hello – I am using fishless cycle to get everything ready in my new tank (10g). I am 12 weeks into it and the second stage (Nitrite to Nitrate) is stalling. Ammonia converts to Nitrite fairly quickly (<1 day) but Nitrate conversion is taking forever. In the last four weeks I saw Nitrate spike up couple of times but Nitrite never really dropped. I think it had way too much nitrite, so I changed the water couple of times to got the Nitrite back to 5-7ppm range. I am not seeing Nitrite to Nitrate conversion anymore or may be it is very very slow.

So, my questions are –

1. Should I just wait until I see a Nitrate spike again?
2. Should I continue to add Ammonia to make sure that bacteria doesn’t starve & die? (Ammonia seems to be converting fast but I am afraid that Nitrite will build up again if add regularly).
3. Anything I can do to help the process move or anyway to check if the process stalled?

Appreciate all the help!
Thanks

PS - Posted this in the Saltwater forum by mistake. Don't know how to move it to this forum so reposting it here.

 

[RussellC]

Geez, that's a head-scratcher.

Perhaps someone who knows more than I will weigh in (I haven't cycled many tanks, and always done mine fish-in).

But the fact that you got nitrates spike at all is, in my view, a good sign.

Did you do anything at all differently that might have upset the cycle after you saw the nitrates rise?

Other than that, the only thing I can say is... be patient.

Not what you wanted to hear, perhaps, but if you got nitrates once, I'm sure you'll get them again.

Good luck!

 

[librarygirl]

What's the PH of your tank? Has it fallen? PH crashes are common during cycling and they can cause the cycle to stall.

I've advise testing your PH and then do a full 100% water change with dechlorinator. Then test the water and see where the levels are (including PH); try to get nitrite to something you can read on the test (<2 is good). Then skip ammonia for a day or two and see if nitrite falls. Then start dosing ammonia again but don't dose to 4, start with 2 and build up. If you post your progress here we can help you as you go along.

 

[talipini]

thanks

Thanks guys for the quick responses. I don't think I did anything unusual during cycling.

Ph has been consistently at 8. I just retested it. Nitrite seems to between 2-5 and small Nitrate. No Ammonia (it has been 4 days since I added Ammonia though). I will wait for a day or two and test again.

 

[librarygirl]

YOu could do the water change anyway; i don't know when the last time you did one was but it's possible the nutrients need to be replenished. Then just dose again but start off slow, at 2, and then once that gets converted move up to 3, etc. That way it will give your nitrite bacteria time to adjust and see what happens.

 

[RussellC]

Thanks guys for the quick responses. I don't think I did anything unusual during cycling.

Ph has been consistently at 8. I just retested it. Nitrite seems to between 2-5 and small Nitrate. No Ammonia (it has been 4 days since I added Ammonia though). I will wait for a day or two and test again.

I would keep adding ammonia. You want to keep the first stage bacteria alive and kicking while you're waiting for the second stage bacteria to catch up.