Spontaneous Nitrate Drop In Fishless Cycling?

[Mamashack]

Sorry if this is the wrong place for this thread but I can't seem to find the new tank section.
I already have a fully cycled 60L tank with platiyes and am now doing fishless cycling in the 30L prior to getting a betta.
I started the process on 17th March and achieved a level of 4ppm by adding Kleenoff ammonia. This level didn't change for 5 days then I added 2 cups of gravel from the mature tank.
Day 6 ammonia was 2ppm, nitrIte was 2-5ppm and just for good measure I checked the nitrAte and that was 20-40ppm. My tap water runs at 0 ammonia, 0 nitrite and 10-20 nitrAte however I'd used some of the mature tank water and that level was 5ppm when the process started and the others were at 0. 
Day 7 ammonia 1pmm, nitrIte still 2-5ppm and nitrAte 40-80ppm
To be honest since then I haven't checked the nitrAtes since and only checked them now because I read in the forum somewhere last night that too high a nitrAte level can lead to nitric acid which can cause the pH level to crash and harm the bacteria causing the cycle to fail. To my surprise it was down to 5ppm and I've done no water changes. If I'd only done the 1 test after a week I might have suspected that it was a false high result but there were 2 results which seemed to support each other.
Day 12 Ammonia 0-0.25ppm last night and nitrItes at 2ppm. Been adding Kleenoff daily to achieve level of 2ppm as I was thoroughly chastised for advising someone else to aim for 4ppm and having read other threads and forums 2ppm seems to be the way to go once the ammonia-munching bacteria have started processing.
I thought nitrAtes levels only went down when you do a water change
[I'd attach the log but it won't let me - says I'm not permitted to upload this kind of file. docx. It's a word document - what format should it be in?]
Any ideas anyone?

 

[Mamashack]

Ok so I've got another situation I don't understand, but maybe it's the cause of the nitrAte drop. Just tested the pH and it's 8.8 or higher - it's been 7.8 until today. Wasn't expecting that and am not really sure what to do about it other than possibly a water change.
Any opinions anyone?

 

[Mamashack]

Topped up the tank to 2ppm ammonia last night and this morning it is only just above 0 so the ammonia-munchers don't seem to be affected by the pH, but could it be inhibiting the nitrIte-munchers? NitrIte still 2ppm and I'll be checking the nitrAte level later

 

[Mamashack]

Ok so the nitrAte is still at 5ppm. Seems I've stumped everyone - lots of views and no comments! lol

 

[the_lock_man]

No replies, because you've confused everyone. There's only two things that I know of that can get rid of nitrate, plants and water changes. Since it can't be either of these, my instinct is to say you're using an API nitrate test, and you've not shaken bottle no.2 well enough.
 
That's the only thing I can think of. When you test again, give that bottle a serious shake for a couple of minutes, bang it on the table, etc.
 
The nitrite thing, I don't know. Try doing a water change, as your pH seems to be dropping, that may well be stalling the N-bacs.
 
I'm sure Two-T Froo-T Amin will be along soon to give us a full lecture on what has actually caused the problem....

 

[Mamashack]

Right I did shake rattle and roll the bottle as per API instructions, but I will retest when I get back in from work tonight. The pH has actually gone up which I can't explain, but I will also do a water change before I add tonight's ammonia dose.
Be interesting to see if our friend does appear! lol

 

[Lunar Jetman]

What's the date of the test kit? They only last about a year once opened.

And what type of decorations/substrate have you got in the tank?

 

[Mamashack]

The expiry is 2017 and I first opened it January this year.


Sorry just checked my log and it was mid February

 

[Lunar Jetman]

And what decorations/substrate is in there?

 

[Mamashack]

Plain gravel, a rock and an artificial Fluval plant with pottery decoration in the middle (see front left signature picture), deltatherm 25w heater 29° and Interpet PF mini filter

 

[Mamashack]

Ok so the nitrAtes are back to 40-80ppm after assaulting my worktop for over a minute with the no.2 bottle and then shaking the final mixture til my arm nearly fell off! Good call, the_lock_man!!! NitrItes still at 2ppm tho.
Done a huge water change and the results before redosing to 2ppm were ammonia 0ppm, nitrites  1-2ppm, pH back down to 7.4
Will retest in 12hrs to see if the ammonia-munchers are still active and see if the water change has influenced the nitrite-munchers at all.
Watch this space!

 

[Mamashack]

Well the 85% water change seems to have had a positive effect. 12 hours after redosing to 2ppm: ammonia 0ppm, nitrItes 0.25-0.5ppm (from 1-2ppm with no further intervention from me) and nitrAtes still at 40-80ppm.
I know that ammonia and nitrItes have to be at 0 for a few days, but have my fingers crossed that tonight's water tests will show a further reduction in nitrItes!
Thanks for pushing me in the right direction, the_lock_man, and for your enquiries Lunar!

 

[Mamashack]

Water test last night showed nitrItes at 0ppm - redosed to 2ppm and 12 hours later nitrIte is 0ppm! yesss!!!!! I know it's early days and I still have the mature gravel to remove which I will do then keep retesting until it's 0 for a few days on the trot!
Getting excited now I can start thinking about getting a betta. Better (groan!) than an Easter Egg any day of the week! lol

 

[Mamashack]

Hmmmm I may have gloated too soon! When I checked the ammonia level this morning after I'd posted the last message - I found that it was 0.5ppm!! After several days at 0ppm after 12hrs from dosing to 2ppm! It was still 0.5ppm after 18hrs. At 26 hrs after dosing ammonia is 0.25ppm, with nitrites still 0ppm. So do I carry on as I have been dosing to 2ppm, adjust the dosing level or do another water change?
I'm really unsure what to do next.