Cycling.. Ammonia Not Going Completely.

[Squid]

Well, my cycles been going for about 4 weeks (not as quick as i would have liked, but ho hum). the ammonia was dropping within a 24 hour period, so i started testing every 12 hours, and adding more ammonia. At first, if i remember rightly, the ammonia was reducing to 0ppm, and the nitrites were still through the roof (so no suprise there then)

Now though, it seems to be acting a little odd. within 12 hours the nitrites are between 0 and 0.25 (i.e. slightly bluer than the aqua of 0, but not as purple as 0.25 on the API test kit..), but the ammonia is not reaching 0, but instead about 0.25 - 0.5ppm.. Does this sound a little strange to people.

Im thinking that perhaps im adding the same amount of ammonia, but the tank is also producing a level of ammonia on its own..?? The are some bits of the Vallis Spiralis plants that have not done too well, but i have not removed them yet.. I thought the cycle was nearly done so i would take them out then. Would decomposing plants cause this ammonia issue, or anything else in the tank? If so, i'll have a good clear out tonight..

Cheers
Squid

 

[annka5]

Yep, I reckon that does sound odd, assuming you've not been adding any chemicals which might destroy the ammonia then it almost looks like your filter bacteria has died back a bit....ARRGGHH!
Can you double check that your filter is working as it should, that the plants haven't blocked it or anything (unlikely) or sand damaged the impeller (unlikely)?
I'd also make sure there's nothing finding its way into the tank that shouldn't, the temp is OK, and remove all dead/dieing leaves in case that's it.
As you can tell, am not sure what the problem is, but that's where I'd start.

 

[Squid]

Thanks annka.. i'll have a look at the filter and have a dead plant tidy up..

Squid

 

[damned]

I had a similar thing happen during my cycle.
When I realised that my ammonia wasn't being used up entirely, I checked my pH, and found that it had dropped from a usually stable 7.2 to 6. This drop seems to be enough to stall, or at least slow down the cycle.
I also checked my KH (carbonate hardness), and this had dropped to zero. From what I can gather, if your KH is low to begin with, the cycling process can 'eat' up the KH. Once this drops to zero, a pH crash can occur.
To fix this pH issue, I performed a water change to bring the pH back up. This then restarted the cycle, and the ammonia was being processed as normal.
Around a week later the exact same thing happened again, and I performed another water change to rectify it.
At this point, I decided to do something about the KH problem, and added some baking soda to raise KH.
I had no more problems for the rest of the cycle.

Hope that some of this helps.

 

[Squid]

i'll take a look at that.. thanks for your help.. and welcome to the board

Squid

 

[Squid]

I had a similar thing happen during my cycle.
When I realised that my ammonia wasn't being used up entirely, I checked my pH, and found that it had dropped from a usually stable 7.2 to 6. This drop seems to be enough to stall, or at least slow down the cycle.
I also checked my KH (carbonate hardness), and this had dropped to zero. From what I can gather, if your KH is low to begin with, the cycling process can 'eat' up the KH. Once this drops to zero, a pH crash can occur.
To fix this pH issue, I performed a water change to bring the pH back up. This then restarted the cycle, and the ammonia was being processed as normal.
Around a week later the exact same thing happened again, and I performed another water change to rectify it.
At this point, I decided to do something about the KH problem, and added some baking soda to raise KH.
I had no more problems for the rest of the cycle.

Hope that some of this helps.

Just checked my PH, and it seems to have dropped to about 6.4 from about 7.6. So it looks like this has stalled the cycle with regards to the ammonia as damned said?

Has anybody else had this problem and performed water changes to rectfiy the problem. ??

Do i take it that once the cycle has finished, that with weekly water changes and not going through the cycle, then i shouldnt continue to have this problem.

Help please.. this cycle is taking a while and im desperate for fish

Cheers
Squid

 

[damned]

Once your cycle has finished, you shouldn't have the pH dropping problem; it's the addition of the ammonia that causes this.
If you can, also check your KH. I'm certain that this will show as zero.
So, do a water change (enough to raise your pH again), and add some baking soda to raise your KH, to stop a reoccurence.
It worked for me, as my cycle finished three days ago.

 

[annka5]

I've never heard that happens! Learn something new everyday. I don't get how the fall in pH causes the bacteria to die off/ stop functioning though..go on, educate me!

 

[damned]

I'm by no means an expert, but from what I've read (and experienced) tanks with a pH of less than neutral cycle much more slowly than those above neutral.
I'll see if I can find a link to some more detail.

 

[pete0403]

Yeah, different bacteria have optimal pH ranges they thrive in just like all other aquatic organisms.

NH4+ (+) O2 --> NO2 (+) 4H+

That 4H+ bi-product of ammonium being converted to nitrite needs to be buffered to keep the pH from falling (as you know, H+ is acidic). If KH falls, so does the buffering capacity.

Sorry if this is common knowledge...

I'd like to know what about cycling causes the KH to fall.

 

[Squid]

Wll i've done a quick water change, which seems to have bought the PH back up to about 7.1, and added more ammonia... so i will test it in the morning and see how things are going.. Fingers crossed I can get the cycle back on track.. The ammonia WAS being cycled within 12 hours and the nitrites down to about .50.. so i was close before this happened.. Oh well, you live and learn..

Thanks very much for your help.. i just wouldnt have been able to figure that one out.

Cheers
Squid

 

[Squid]

Well.. this morning, the nitrites were a little higher, but the ammonia is going back down again.. so it looks like i might be back on track..

Do i understand all of this KH PH thing and how it affects the bacteria,NO.. im a i thankfull it seems to be sorting it out though.. OH YES..

i understand that excess nitrates (as i was almost through the cycle) may have also caused the PH to drop.. so that might be it too..

I wonder how many other people have been affected by the PH of thier tap water, and how much of a factor this has been on different peoples lenght of their fishless cycle.

Cheers
Squid

 

[annka5]

I've a v low KH and a pH of 6.4 from the tap, my cycle did take a while but the pH etc didn't drop.
I guess that decomposition increases acidity (erm, hydrogen ions?) so it would make sense that cycling would have the same effect. Normally as nitrate rises pH will fall a littleand with not doing water changes as you're cycling...
Am now wondering why mine didn't change!