Fishless Cycling - Argh!

[Ruthc1985]

I bought a new 19 litre tank just over 3 weeks ago.
 
Did all the usual stuff, washed the gravel thoroughly before putting it in, dechlorinated my tap water and dosed with ammonia to 3ppm. 
 
The following day a fellow fish keeping friend gave me a squeeze from her filter sponge, I began to see results very quickly within a few days, with my nitrites and nitrates climbing (nitrites went to 3-4ppm, nitrates at approx 20ppm). As the ammonia dropped, I topped it up with a tiny amount to return it to 3ppm, continuing to seed with the bottled bacteria (I know many think they aren't much use, but I had the bottle in and thought I might as well use it!). .
 
Then it stalled for getting on for two weeks now. But I noticed something odd last night when testing the water. The nitrites and nitrates had vanished. I have no live plants to use nitrates. And no obvious algae. I am also pretty confident in my test kit as I was getting the same result consistently for days.
 
I did also observe a small bacterial bloom over the last week (water went slightly milky) which vanished yesterday
 
So, after 3 weeks my levels are currently:
 
pH 7.8
Ammonia 3ppm
Nitrite 0-0.25ppm (having been 3ppm a few days ago)
Nitrate 0-5ppm (having been 10-20ppm a few days ago)
 
No live plants, temp set at 27 degrees C.
I am using the API test kit for everything, and also have the JBL nitrate test kit.
 
How can the nitrite and nitrate vanish?! (I have also double checked the nitrates on several occasions with a JBL kit alongside the API test kit)
 
 

 

[Ch4rlie]

Have you done any water changes?
 
Do continue to do testing and post results.

 

[Ruthc1985]

No water changes. I've been reading that the API test kit can give false results when nitrite goes very high - wondering if this has happened?

 

[TwoTankAmin]

There is more to this story than your are reporting. In order for somebody to be able to figure out what might be going on it is important to provide as much information and detail as possible.
 
You bought the tanks 3 weeks ago and after that the time line and details get scant. Did you set it up and add the ammonia that day? The next day? A few days later. What are your tap parameters? What dechlor are you using and at what dosing level? What fisless cycling guide are you using? What was the bottled bacteria? What were all the test results in progression? How did you calculate the amount of ammonia to add.
 
Bacterial starters that contain only spores can aid in a bacterial bloom.
 
The nitrite is supposed to vanish in a cycled tank. Nitrate should not vanish it needs to be dealt with via water changes, plants or, in some cases, denitrifying bacteria.
 
A nitrate kit works by first converting the nitrate to nitrite. This means nitrite in a tank affects nitrate test results.

 

[Ruthc1985]

Hi TwoTank Amin,
 
Tank was bought 3 weeks ago (probably just over that now). I added the ammonia two days later when I got hold of some. I used the calculator listed on this site to calculate the volume to add, and after allowing the ammonia to mix and circulate, tested the ammonia level to ensure I hadn't overdosed, and the test confirmed I had added to 3ppm. At the same time, I added the contents of the filter squeeze from my friend's established tank.
 
The dechlorinator I am using I can't remember the exact name of, it's a standard tap safe treatment for dechlorinating fish tank water - I add a capful (5ml) to 20 litres of water and scale up or down appropriately. This was added with the water at the very start.
 
Tap parameters - 0 ammonia, 0 nitrite, between 0 and 5 nitrate.
 
As for all the results in sequence - I simply don't have that info, I test, look and then bin the test result making a mental note of what happened for when I test the following day. So that's all the info I can give you there sorry.
 
My nitrites and nitrates began to climb over time, and my ammonia dropped, and I topped the ammonia back up to 3ppm to feed the bacteria, and then it stayed there for the last week, then it was yesterday I noticed the nitrite and nitrate had vanished. As you say nitrite should decrease, but nitrate shouldn't - hence my confusion. And it also vanished overnight - not over a matter of days.
 
The guide I am using is http/www.fishforums.net/index.php?/topic/421488-cycling-your-new-fresh-water-tank-read-this-first/ but I have never got beyond dosing with ammonia for the second time.
 
The bottled bacteria is called Interpet Filter Start - as I say I know many don't think they work.

 

[Ruthc1985]

So the thing I mentioned about the API test kit giving false positives at high levels may infact be true!
 
I've just tested my tank water, and yep, another apparent zero reading. Diluted tank water 1:5 with tap water: nitrate reading of around 1ppm. (tap water reading alone is 0ppm). Very slight nitrate reading too, and Ammonia at around 2ppm. So maybe things are on track afterall