The Missing Nitrite

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macphyter

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   I've been reading this forum for weeks now, and I feel like I have a pretty good grasp on the chemistry of the fishless cylcing, although I'm still a beginner.  I started cycling my first tank recently, and something is not quite right.  Here's the stats:
 
20 gal tank, Aquaclear 50 filter, 2 inches of gravel, and artificial plants.
 
I set it up and added 2.25 mL of 10% ammonia solution (no surfactants), and got these readings using API master test kit.
Day 1:  Ammonia-3.0ppm, Nitrite-0, Nitrate- 5.0, PH 8.0
 
I've been testing every day, and the ammonia stayed at 3.0 until day 13-
Day 12: Ammonia-3.0, Nitrite-0
Day 13: Ammonia-2.0, Nitrite-0
Day 14: Ammonia-2.0, Nitrite-0
Day 15: Ammonia-1.0, Nitrite-0, PH 8.2, KH 196.9, GH 35.8
Day 16: Ammonia-0.5, Nitrite-0
 
I understand the cycle enough to know that this is impossible- where is that ammonia going if its not being converted to nitrite?
In order to gather more information, I bought an API water hardness test kit, and got the additional info on Day 15.  Should I be worried about the very high KH value?
 
It looks like my ammonia test is working properly, because its going down right on schedule, but the nitrite test results are clearly wrong.  I've followed the instructions VERY carefully, but I never see any shade of purple, always the same light blue color.  My best guess is that maybe my Nitrite test liquid is bad.  The expiration date on the bottle is 05/2018, but is it possible that its just bad?  When I first opened up the kit, I noticed that the nitrite test bottle lid was not screwed on very tight because when I shook it, some leaked out.  Could it have gone bad from sitting on the shelf in the store with a loose cap like that? 
 
Does anyone have any other theories?  If not, I may just go buy a new nitrite test kit to see if that's the problem.
 
 
 
I've had a faulty API test kit. Would read 0 Nitrate all the time. I'd go get it tested in the fish shop and if it's a different reading - get them to give you a new one :)
 
You have a good grasp on the process. You are correct that if the ammonia drops the nitrite should rise.
 
There is no way a new kit bottle top should be loose as you described. I would bet you are again correct in your assumption. While you are entitled to a replacement bottle, good luck with that. I would just accept you got screwed and buy another nitrite kit. You can try for a replacement, but it is more important to have accurate readings here than to worry about losing a smallish amount of money on a bad nitrite kit.
 
KH is not of a concern during cycling unless it gets too low. It represents the organic carbon which the bacteria must have to function. Normally, the API kits read GH and KH in degrees, I am wondering what factor you used to calculate the measures as normally GH is the higher of the two. Normally, it is about 17.9 (multiply # of drops by this factor for both). KH is basically what holds pH steady. As  rule the higher the pH, the harder the water and vice versa.
 
ech0o said:
are your nitrates going up?
My nitrates have stayed at 5.0, but thats a good question.
OK, I bought a whole new test kit today, and performed the nitrate test again.  It still is reading zero!  Now this is a big mystery.  My ammonia is reading a solid 0.5, so I know it has gone down. Could there be something in my water that's messing up the nitrate test?  Or could the nitrates be off the chart, causing a false reading?  This is very strange.
 
Forget nitrates. Those kits are awful.
 
What you need to be seeing is nitrite. Unless you see nitrite first, you won't see nitrate anyway.
 
TwoTankAmin said:
Forget nitrates. Those kits are awful.
 
What you need to be seeing is nitrite. Unless you see nitrite first, you won't see nitrate anyway.
 
Oh, sorry.  It was a typo...  I meant to say I tested for nitrite again, but its still showing zero with the new test kit. 
 
Hmmm, this is rather strange!  I would probably dose back up to 3ppm and continue to see if you get any nitrite showing.  My only question is whether you have any live plants in the tank?  What are the conditions in there - Is it a bare tank with just a filter?
 
214jay said:
Hmmm, this is rather strange!  I would probably dose back up to 3ppm and continue to see if you get any nitrite showing.  My only question is whether you have any live plants in the tank?  What are the conditions in there - Is it a bare tank with just a filter?
 
There are no live plants, just some plastic plants, some rock caves from the LFS, and gravel. I have a bubbler that I turn on now and then, but its just for show because my HOB filter seems to break up the surface tension pretty well.
 
For the past four days in a row, I've measured ammonia: 0.5, nitrite: 0.  I've tried both the old and new test kits, and I still get 0 nitrite with both.  I've been tempted to do what you said, dosing back up to 3 ppm, but first I'm going to take a sample of my tank water into the LFS tomorrow and see what they get.  There's only two conclusions here-  either I really don't have any nitrite, or else my test kits are both faulty.  (I suppose I could be doing the test wrong, but its pretty straightforward, I can't imagine I've misread the instructions)
 
I would be very surprised if both test kits are wrong and as you say very easy test to do as long as you wait the 5 minutes after mixing.  Sometimes strange thing happen during fishless cycles so after you get the test done at the LFS I would dose back up to 3ppm.
 
   So, I just returned from the LFS (in this case PetSmart), where I had my water tested.  I went to the fish section and asked to speak with the resident fish expert.  This employee said "That's me!", so I proceeded to describe my problem.  As soon as I mentioned a fishless cycle, she suddenly didn't seem so confident.  After describing the situation, she agreed to test my water for me.  As she got the supplies, she asked me "So, why don't you want fish in your cycle?"  I resisted the urge to turn and walk out of the store, and instead explained why its actually less work to do a fishless cycle.  She suggested getting a couple of hardy goldfish, and then "getting rid of them" when the tank cycles, and I politely declined. :)  Then she pulls out some test strips to test my water, while also admitting that my API liquid test kit is probably more accurate.  Still, her results were the same as mine-  ammonia 0.5, and nitrite 0.  As we chatted some more, I realized that after just a few months of reading this forum, I now know more about cycling a tank than this supposed "fish expert".
 
   Last night I watched the Dr Tim's video where he demonstrates that the API nitrite test can indicate zero, when its really just off the scale.  I know its a long shot, but I missed a couple days of testing right about the time the ammonia started dropping, and perhaps the nitrite went from zero to off the scale in those couple of days, and that's why its showing zero.  Just to verify, I'm going to get some DI water and perform a diluted test to see if anything shows up. 
 
If that doesn't work, then I guess my only course of action now is to re-dose up to 3 ppm, and keep waiting for the nitrite to show up.  If that doesn't work, then I guess I can always empty the tank, clean the filter, and start all over.
 
OK- but here is the thing. 3 ppm of ammonia if completely converted to nitrite and testing both with API kits means the most nitrite you can have is 7.65 ppm. That is not high enough off the scale for it to read 0, it should still  read 5 ppm.
 
At your pH the KH should be fine as well and you are oxygenating the water. I could understand if the ammonia refused to go down. that vcan be explained by no bacteria coming in with your tap water. But the bacteria comes inside bits of the biofilm which will contain both kinds. So ammonia down should lead to nitrite.
 
Also drop the ammonia dose to 2 ml. You need to allow for the glass and the decor. The tank wont hold 20 gals. even if you filled it to oveflowing. (Run the tank at 18 gal. in the ammonia calc.)
 
So I've continued to struggle with this mystery...  I dosed with ammonia back up to 3 ppm about 8 days ago, and the ammonia level has stayed there ever since.  Also, there is still no nitrite showing up in the test.  I've decided that my tap water must not have any nitrifying bacteria to begin with, and that explains why I've never seen any nitrite.  
 
A couple weeks before I filled the tank, my city had a strange water problem-  some people were complaining of a strange smell in their water, and the city water officials didn't have any explanation, but they said they were working on it.  My theory is that in order to combat this, they probably did something to the water to really "clean it up", perhaps removing any trace of nitrifying bacteria.  Now, I know TwoTankAmin is going to reply with a comment about how most of the bacteria comes from the local house plumbing, not from the water main. ;)   That may be true, but I'm just hunting for some possible explanation for all this.
 
Still, none of this explains why my ammonia level went down.  Its just a big mystery.  In any case, the lack of nitrite means there's no nitrifying bacteria, so I've finally given in and ordered a bottle of Dr Tim's to get the ball rolling.  I'll empty the water and start over, and hopefully get things sorted out so I can finally go shopping for fish!
 
Couldn't find the question above so Ill ask it :D
 
Do you do water changes while you are cycling ?
Prob answer is "NO" but though I would ask...
 
As to your missing nitrite, did you test for nitrAte yet ?
 
When doing a fishless cycle water changes are to be avoided unless something goes wrong. Usually this involves one of two things, A pH drop to put it close to 6.5 or lower or else too little KH (where the inorganic carbon the bacteria need come from). Usually a water change will restore these.
 
The other time a water change may be needed is when ammonia is over dosed. This may make it to being an overdose of nitrite which also requires a water change.
 
mac be sure to read the directions for doing a fishless cycle using Dr Tim's on his site here http://www.drtimsaquatics.com/resources/how-to-start
 

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