What Happened?

[ac700wildcat]

I just cycled my new 40 gal doing a fishless cycle. It has been processing 3ppm of ammonia to zero in four or five hours. A few days ago the nitrites finally dropped to nothing. I kept adding ammonia, the nitrites kept staying at zero, and nitrates were off the scale. Earlier tonight I turned everything off, put all my filter media in a bucket and filled it with water from the tank. I then proceeded to drain as much water as possible leaving at the most two gallons of the original water in the substrate. I re-filled the tank using 2/3 RO water and 1/3 dechlorinated tap water and put the filter media back in and got everything running.

I wanted the water to get to the proper temp before adding fish, and beings that was going to take some time I decided I should add some ammonia to keep the bacteria fed. I put in enough to take the ammonia up to 1ppm. There are some nitrites in my tap water to start with (.5ppm), so I expected to maybe have a bit of nitrites in there when I tested the water a little bit ago. My tests came up to be 0 ammonia, 1 nitrite, and between 5 and 10 nitrates. Why do I have so many nitrites now after the bacteria were eating it up before the big water change? Should I add more ammonia now and keep monitoring levels until nitrites drop again or just wait til they go away?

Thanks,
Matt

 

[OldMan47]

Don't test immediately after a water change, especially one that big. Give it a few hours for things to stabilize and then test. You may have stirred something that was in the substrate and now it is being processed as a spike in inputs.

 

[waterdrop]

Completely agree with oldman47.

Plus, any time you do something like moving the media out of the filter, into a bucket and back again, you must expect the possibility of a mini-cycle with the system taking even a day or two to get back to its normal state.

~~waterdrop~~

 

[SOLEXIS]

Hi
If your NO3 level is high it means you haven't got any anaerobic media in your filter. Try the Bionitratex from JBL, that's perfect.
I would suggest to stop adding things in your tank except some bacteria (Denitrol, I am a JBL addict !)
Then wait few days, make a water test and gradually stock your tank if the water chemistry is OK. Continue to add some bacteria during 5 days to stabilize your tank.
Good luck

 

[ac700wildcat]

I tested the water for nitrites five hours after my post and there was no change in the level. Not knowing how long the bacteria that process the ammonia can go without ammonia I added enough to get it back to 3ppm again. Now twelve hours later the ammonia is once again gone and nitrites are up even more to 5ppm. Enough of the bacteria must have died off enough to really slow things down again? Should I keep adding ammonia until I see the nitrites drop again?

 

[ac700wildcat]

Now I just read another post and found out I'm only supposed to be adding the ammonia one a day? I had been adding ammonia to this tank up to four times a day to bump the levels from 0 back up to 3ppm. So should I wait until the same time I added the ammonia yesterday to check and add any more?

 

[redevilman]

You need to keep adding ammonia daily to get a reading 0f 5ppm then your you nitrites will spike and hopefully go back to 0ppm pretty quickly. keep adding ammonia for a further week to be on the safe side then do a large water change to get your nitrates down and go get your fish.

 

[redevilman]

Now I just read another post and found out I'm only supposed to be adding the ammonia one a day? I had been adding ammonia to this tank up to four times a day to bump the levels from 0 back up to 3ppm. So should I wait until the same time I added the ammonia yesterday to check and add any more?

Just add ammonia once every 24 hrs . When they are down to 0ppm in less than twelve hours after you added ammonia your cycled.

 

[ac700wildcat]

The ammonia has actually been going down to zero from 3ppm in less than six hours and actually closer to four. The nitrites had spiked and then dropped to zero for a few days even tho i was adding ammonia four times a day. Thats when I did the big water change and now have nitrites again that are processing slowly. The ammonia still processes really fast tho. I'll wait another twelve hours, so that is has been 24 hours since the last addition of ammonia and test everything and add again.

I was excited too, it would have been a two week cycle if things woulda worked out yesterday. I had started with a ton of media from other filters. I actually have part of the fish for this tank already. I purchased them because they probably weren't going to be available when the tank is ready, Right now they are in a tub with a cycled filter getting regular water changes to keep them healthy until they can go into my new tank.

 

[waterdrop]

For whatever reason, you sound like you are potentially back in the "nitrite spike" stage of fishless cycling for the moment and redevilman is giving the correct advice. Even though you are focused on the goal of the filter dropping 5ppm of ammonia and the resulting nitrites to zero within 10-12 hours, you should only add the ammonia once in a 24 hour period.

One of the reasons it is recommended that you continue to fishless cycle the filter for another week after you reach this goal is because it is apparently fairly common for the nitrite processing population to seem to pass the test, but then to have a setback like this. It is much better to catch this and be able to continue to fishless cycle, rather than already have the fish in there and have to begin large water changes up to twice a day.

Be patient, check your pH and make sure its not crashing, and just test and keep accurate logs. A very common pattern people use is to test in the morning, then add the necessary ammonia to get the level up to 4-5ppm, then test 12 hours later in the evening and see if both poisons have dropped to zero. Usually there is a long period where ammonia will have dropped to zero in the evening test but nitrite will still be showing at some level. Then in the next morning test, nitrite will have finally dropped to zero. You add ammonia again that morning and repeat.

~~waterdrop~~

 

[ac700wildcat]

I'd just like to say thanks for the help so far. Its been 24 hours and the nitrites are gone, so I added enough ammonia to get back up to 4-5 ppm and will test again in 12 hours to see where I'm at. I'll take your advice and let the cycle go for a week or so once I'm down to no nitrites in 12 hours. I have $60 worth of fish that I would like to keep alive.

 

[waterdrop]

You sound like you are in a bit of a balancing act here. You'll need to watch things carefully I suspect. At some point the conditions in the bucket could get to be worse for the fish than the almost cycled tank (hopefully not but I'm just saying it can't hurt to watch it closely.) If the nitrite processing is getting very, very close to 12 hours, then the performance of the new filter after the big water change may be good enough and it will be better to go ahead with the move - you just have to do all your tests on both environments and make a judgement call I would think.

~~waterdrop~~

 

[Miss Wiggle]

You sound like you are in a bit of a balancing act here. You'll need to watch things carefully I suspect. At some point the conditions in the bucket could get to be worse for the fish than the almost cycled tank (hopefully not but I'm just saying it can't hurt to watch it closely.) If the nitrite processing is getting very, very close to 12 hours, then the performance of the new filter after the big water change may be good enough and it will be better to go ahead with the move - you just have to do all your tests on both environments and make a judgement call I would think.

~~waterdrop~~

I agree

Solexis - Sorry to say this but I'm getting a little bit suspicious of your motives on this forum, every single post from you has been rabbiting on about this JBL stuff. OK I appreciate it if you are trying to help people out, and if you have found a method that works for you that's great. But your starting to look like an advertising spammer to be totally honest!