I am on day 19 of my fishless cycle on a 10 gallon tank. I used a ton of seeding material and up until now, I have not had a single nitrite reading. 4ppm ammonia was taking about 36 hours to get down to .5-1.0. In the meantime, I had tons of nitrates so I knew I was on the right track despite my lack of nitrites. 2 days ago I had a pH crash and had to do a 50% PWC to restore the buffers and stabilize the pH. I used Prime with my PWC, added my ammonia back up to 4ppm. The nitrates were down to 40. Yesterday was the first day I was able to process 4ppm down to .25ppm in 24 hours. I didn't test for the nitrites at the time because I assumed I would not get a reading as usual. The nitrates were around 80. Todays test showed I again processed 4ppm down to .25ppm in 24 hours but, this time I decided to test nitrites too. (API Master Freshwater) To my surprise not only did I have nitrites, they were likely reading off the chart. Def greater than 5. The nitrates were also back up quite high as well and I imagine tomorrow they too will be off the charts. I know my end goal is to be able to process the 4ppm into a 0 ammonia 0 nitrite reading within 24 hours. Im starting to wonder if something went wrong in the cycle with this sudden surge of nitrites. Best case scenario I will test again tomorrow and actually process the full 4ppm of ammonia AND show no nitrites but... what does it mean if I do end up with a reading of 0 ammonia and still tons of nitrites? Do I need to do yet another 50% water change already to bring the nitrites and nitrates back down into readable levels? Just when I thought I was on the brink of getting the fish in the tank, I run into yet another issue. I have read that too high a level of nitrite will halt the cycle. Is this true even with the existence of high levels of nitrates? How can I work on getting these nitrites processing as quickly as they previously were?
Nitrite After PWC
- Thread starter Jayann
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Mebbid
Aquarium Advice Addict
The bacteria that processes ammonia tends to grow faster than the bacteria that processes nitrite. You are just seeing a population surge in bacteria from the huge levels of ammonia and the other bacteria just hasn't had time to catch up. Since you're seeing a ton of nitrates already I doubt it would take much longer for everything to even out.
A water change won't hurt and will make things a bit easier for you.
A water change won't hurt and will make things a bit easier for you.
Over the last 24 hours I finally processed all 4ppm of ammonia. The nitrites were still reading very high at least 5. I did another PWC I would say about 90 percent because I had another drop in pH (not quite so dramatic this time). I added my prime and am waiting to run another test to see how much the nitrites have lowered. I read in another thread that once the ammonia is processing in 24 hours, you can begin working on getting the nitrites processed within 24 hours by getting the nitrites to around .25 with the water changes. It suggested adding only 1ppm of ammonia to start to not overwhelm the nitrites and try to get it to process the nitrites that are the result of 1ppm over 24 hours. It then suggested once this is successful, to increase the ammonia to 2ppm to try and get the nitrites from that processed within 24 hours and to keep up the process by adding 3ppm and 4ppm as the nitrites are able to be turned over in the 24 hour period. Now mind you I did not have 2 consecutive tests showing 4ppm processing within 24 hours. But I have been so close to getting it all processed within the 24 hour mark that I don't really doubt that I would have the same results tomorrow. My question is, should I just go ahead and dose right back up to 4ppm to be sure I have a 2nd consecutive day of processing it within the 24 hours or should I go with the other suggestion of working back up to the 4ppm so I can focus on getting the nitrites processed too?
Mebbid
Aquarium Advice Addict
I would just keep dosing the ammonia to 4 ppm and completely ignore nitrates. The nitrates wont bother your cycle. This way you have plenty of food for your ammonia consuming nitrates and there wont be any shortage at all of nitrites.
Also, the pH will tend to shift during the day / night cycle so keep that in mind.
When you say ignore the nitrates, were you meaning nitrites? It isn't the nitrates that are concerning me, it is the nitrites. I want to be able to process the 4ppm ammonia without having any nitrites being tested either to consider my cycle complete correct? I think what you are saying is to not worry about the nitrites being high at the moment and to just continue as I have been and eventually I will be seeing both the ammonia and the nitrites being fully processed in the 24 hours?
I think my desire to research may get the best of me at times. I keep reading about nitrite spikes, nitrite walls and other topics regarding issues with nitrites processing in general. Rather than being patient I am assuming this is the kind of thing that is happening to me since I have lacked nitrites through out. I think this lack of experience with seeing the nitrites has simply got me over thinking their presence at the moment.
Either way, I have dosed back up to 4ppm and have the nitrites to where they will be in a readable range at least with that last water change. I will see what becomes of it 24 hours from now
. Thanks for all the help 
Mebbid
Aquarium Advice Addict
Most people, myself included, do a single water change when doing a cycle in order to put the nitrites at a readable level when the ammonia starts getting cycled through. As long as they aren't way off the charts I wouldn't worry about them too much.
Also, I did mean nitrates.. I just mistakenly read one of the nitrites as nitrates instead There were a lot of nitr*tes to read through
Also, I did mean nitrates.. I just mistakenly read one of the nitrites as nitrates instead
There were a lot of nitr*tes to read through 
Thumper828
Aquarium Advice FINatic
My cycle is in the exact same stage. Thanks for posting!! I was wondering the same thing.
Mebbid
Aquarium Advice Addict
I know how you feel. I cut my fishless cycle short just to get fish in thankfully it was far enough along so that it didn't cause any problems
thankfully it was far enough along so that it didn't cause any problems
What is strange is you said you added a lot of seeded media which means you already had BB in the tank which would have explained why you didn't get any nitrite readings (that bacteria was in enough abundance to process the ammonia down to nitrates.
So I'm surprised you seem to be cycling again. You said you had a ph drop? You know if ph falls to below 6.5 biological activity slows and at 6 it stops and BB begins to die off. Could this have happened?
So I'm surprised you seem to be cycling again. You said you had a ph drop? You know if ph falls to below 6.5 biological activity slows and at 6 it stops and BB begins to die off. Could this have happened?
According to my notes, the pH drop occurred within a 21 hour period from 7.4 to 6.4. As soon as I noticed the drop, I went for the 50% PWC to restore the buffers so it is entirely likely it was slowed significantly sometime within those 21 hours. After my PWC I was back up to 7.2 so I don't believe it would have stopped entirely at any point. The most recent drop in pH was 3 days after the 50% PWC and it dropped to around 6.6 so I was trying to prevent it from getting to the 6.5 mark or below. It is just after the initial 50% PWC that was done, to manage the pH, that I saw the nitrites. This most recent PWC was again done to try and get the pH in check but also so I could get the nitrites within readable levels. Today the pH is 7.4 so that is ok. It is currently processing the 4ppm ammonia I added last night so I will not know until my 24 hour later test, that will be completed this evening, where the nitrites will stand. I do know that after the most recent water change, I did not have a nitrite reading though it was a significant 90% PWC.
I guess that then goes back to my initial concern of why I was able to process the ammonia to nitrate without seeing the nitrite (lots of seeding material as I expected) but now suddenly so far into the cycle, the nitrites are not processing as fast as previously. If this is indeed due to the 6.4 pH, has this completely screwed up the cycle? Or is this just more of a bump in the road?
LOL!!!
Out of curiosity I performed a couple tests at what would be the 12 hour mark. Ammonia is down to .5 from 4ppm. Nitrites were not off the charts but were pretty close looking to the 5ppm mark. Nitrates were at 80ppm. I somehow doubt the nitrites are going to hit the 0 mark in the next 12 hours. Since 1ppm of ammonia is enough to keep the bacteria fed until fish are introduced, would it be such a terrible idea to give the above idea a try where I limit my ammonia dosing to baby the nitrites and not overwhelm them again with the 4ppm dosing? The idea is to work back up to the 4ppm dose after you know that you can process the nitrites from 1ppm, 2ppm etc. in the 24 hours from how I understood it. Of course this would require yet another PWC to get them below .25ppm to start the process. I know the guides say the PWC do not hurt but it sure worries me to think about doing yet another when I know I will still need yet another one at the end. Also what about adding another small pinch of fish food? I know this is suggested for providing nutrients for the bacteria but I don't want to do it if it's just going to encourage more nitrites.
Are you saying I should re-dose at 1ppm even if its less than 24 hours?
No I meant after 24 hours.
Thumper828
Aquarium Advice FINatic
Amazingly the nitrites actually did go down quite a bit within the last 12 hours since I tested. It's not quite at 0 yet but after the 24 hour mark my results were 0 ammonia, somewhere between .5 and 1.0 nitrites and 80 nitrates so I was happy to see it headed in the right direction. Hoping this is the begining of the end
Mebbid
Aquarium Advice Addict
Amazingly the nitrites actually did go down quite a bit within the last 12 hours since I tested. It's not quite at 0 yet but after the 24 hour mark my results were 0 ammonia, somewhere between .5 and 1.0 nitrites and 80 nitrates so I was happy to see it headed in the right direction. Hoping this is the begining of the end
Very nice! Just about there
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