Fishless cycle completed - no fish - now a nitrIte spike?

[beatlesfan317]

This question is in regards to nitrItes, not nitrAtes.

Background: I fishless cycled my tank, using Ace Hardware Ammonia and it seemed to go pretty
well and normal. Cycle completed today at noon. I kept the ammonia levels at 3ppm at all times,
ammonia hit 0 on day 24, nitrIte showed up on day 20 and spiked on day 26, by day 30 nitrItes
fell from 5ppm to 1ppm over 24 hours, kept dosing ammonia to 3ppm, nitrIte was down to 0.5
on day 31, 0.25 on day 32 and 0 today (day 33). This is the definition of a cycled tank everywhere
I read.

Following fishless cycle instructions, today at noon (when I tested daily), ammonia was 0, nitrite 0,
nitrate 80. I filled clean buckets with water for a water change and dosed API stress coat in the buckets
and let the water set for 2 hours to dechlorinate and stabilize the temperature. 2 hours later I did the
70% water change, and at 6 tonight, tested the aquarium water - ammonia 0, nitrIte = 5, nitrates 40.

How is this possible, the nitrites going up to 5? There are no fish in the tank and I did not add any
ammonia since it reached 0. I'm so glad I had my wife verify at noon that she agreed, nitrites were 0
and we agreed the tank was cycled. Even if I had some nitrites then, shouldn't the 70% water change
have decreased them a lot but instead I'm getting 5ppm nitrite spike now when it was 0 six hours ago.

I'm using the API freshwater test kit. Ph is stable at 7.6. I also checked the water out of my tap - 0 nitrItes.

Any advice?

 

[itiwhetu]

Have you got plants in this tank. If not load it up with plants 30-50% of the volume. Wait till the plants start growing ( 10 Days ), add fish a few at a time. Cycling complete.

 

[beatlesfan317]

Well, I'm worried this could be my problem. Found this on another forum:

Well, when I tested earlier and my wife and I both thought the cycle was complete - the test tube turned purple first (toxic) but by the required 5 min mark it was blue (safe) ***this is important. Well, I found this: "The API Nitrite Kit is designed to provide accurate results from 0 to 5 ppm (mg/L).Under even more extreme conditions, the API Nitrite Test Kit can be overwhelmed. As an example I share the following to provide a better understanding of the API Nitrite Test Kit (liquid reagents): At 5.0ppm (mg/L) the test result reads as 5.0ppm (mg/L) Nitrite At 50ppm (mg/L) Nitrite, the test result turns deep purple initially, but back to light blue after 5 minutes." That's what my test did. Maybe my cycle wasn't completed.

 

[beatlesfan317]

No, I don't not have any live plants.

 

[itiwhetu]

Don't over think this.

 

[itiwhetu]

How is a cycling process going to happen with no biological activity happening in your tank. Add plant start that activity.

 

[mcordelia]

@beatlesfan317 you can test the theory of high nitrites stalling the cycle by dosing 1ppm ammonia and seeing what happens after 24h.

 

[Essjay]

The definition of a cycled tank is one which can clear 3 ppm ammonia to zero ammonia and zero nitrite in 24 hours.

If you kept the ammonia level at 3 ppm all the time, presumably you added more whenever it dropped? If you did, you will have stalled the cycle. The nitrite eating bacteria stop growing once the nitrite level exceeds 15 to 16 ppm, and since 1 ppm ammonia is turned into 2.7 ppm nitrite, it doesn't take much ammonia to to reach and pass stall point.

The best thing you can do is another very large water change - if possible, remove all the water down to the substrate. This should reset the levels back to almost tap level, though there will still be some nitrite in the water in the substrate.

Then read this https://www.fishforums.net/threads/cycling-your-new-fresh-water-tank-read-this-first.421488/
You will notice that with this method, ammonia is only added once certain targets have been reached. It was written so that if followed, nitrite can never reach stall point.
I suggest you add a 3 ppm dose of ammonia but instead of testing every third day, test every day. As you already have all your ammonia eaters you will probably have readings of "ammonia under 0.75 and nitrite above 2ppm" the following day. If this is the case, add another 3 ppm ammonia (dose #2 in the method) and then follow that method from there.

 

[beatlesfan317]

Thanks for the response. I added ammonia whenever it dropped below 0.5ppm, which for the past 8 or 9 days
was every 24 hours. You hear different things, some people swear that no ammonia or nitrite spike will interfere with the cycle and others say the exact opposite. I was following this page - supposedly by a bunch of PhD's that swear it doesn't interfere. https://aquariumscience.org/index.php/2-1-fish-less-cycling/

I will check out your link. Thanks.

 

[Essjay]

The 'add ammonia every time it drops' method is the one everyone used when fishless cycling was first invented. But it was then realised that high nitrite prevents the nitrite eaters from growing. TwoTankAmin, who wrote the method on here, did a lot of research and I think he even communicated with Tim Hovanec who discovered which species of nitrite eaters grow in our aquariums. He discovered that the bacteria don't die if they are not fed which means that ammonia does not need to be added whenever it drops low.

 

[beatlesfan317]

The 'add ammonia every time it drops' method is the one everyone used when fishless cycling was first invented. But it was then realised that high nitrite prevents the nitrite eaters from growing. TwoTankAmin, who wrote the method on here, did a lot of research and I think he even communicated with Tim Hovanec who discovered which species of nitrite eaters grow in our aquariums. He discovered that the bacteria don't die if they are not fed which means that ammonia does not need to be added whenever it drops low.

That is good to know because I think everyone worries after completing the cycle and changing water, how long do I have to get fish in the tank and if the tank isn't fully stocked will the bacteria die. I think most agree the bacteria will not die, at least not anytime soon.

 

[Essjay]

The method on here does say

If for any reason you are unable to stock the tank when it is cycled, you can continue adding ammonia to keep the tank cycled. For this you should add the 1/3 snack amount every 2-3 days. The bacteria do not need to be fed every day and will be fine. Don’t forget the water change before adding the fish.

Once upon a time, it was believed that the bacteria would die within 24 hours if they weren't fed. We now know they don't die. If they are not fed, they go dormant after a few weeks, finally dying several months later.