Relentless Nitrite Spike During Fishless Cycle

[vidocha]

I am currently cycling my 55gl tank with 2ppm Ammonia, I also added Seachem Safe during 1st week per directions on the bottle, and I added BioHome Ultra media and threw in their Starter Balls.

My Ammonia went to 0ppm after 3 weeks. But now I have a big Nitrite spike since the last 6 days, and my Nitrates aren't budging. As an experiment I added 3 eye drops of my aquarium water and filled the rest of my API test tube as normal, and the Nitrate readings were still around 5ppm! I have been adding Ammonia back into the tank every 2 days, because within that time my Ammonia goes to 0ppm

Should I do a water change at this point? Should I stop feeding Ammonia? Or should I keep my regimen going?

[SNap0283]

This is normal. In about 3 weeks the ammonia will drop and Nitrite will spike. It will take another 3 weeks before Nitrite will drop and your nitrate will rise. Normally it is left alone until ammonia and nitrite are both 0 then you will do a 100% water change and then make sure a 2-5ppm of ammonia will go to 0 within 24 hours, then it is safe to add fish after another 100% water change.

If you do a water change now it will remove some of the bacteria that you are trying to grow so you are better off just letting the process play out.

[vidocha]

This is normal. In about 3 weeks the ammonia will drop and Nitrite will spike. It will take another 3 weeks before Nitrite will drop and your nitrate will rise. Normally it is left alone until ammonia and nitrite are both 0 then you will do a 100% water change and then make sure a 2-5ppm of ammonia will go to 0 within 24 hours, then it is safe to add fish after another 100% water change.

If you do a water change now it will remove some of the bacteria that you are trying to grow so you are better off just letting the process play out.

Appreciate your feedback. I knew there would be a Nitrite spike, but didn't expect it to be this high. Thanks for the input.

[DJW]

At this stage you can cut the ammonia doses back to 1 ppm per day. That way the nitrite won't climb as fast. When the nitrite gets really high it can inhibit the growth of the bacteria you are trying to encourage. The tank will still cycle but it will cycle a bit faster if you change the water when the nitrite gets way off the chart. When I measure for nitrite using 1/2 tank water and 1/2 clean water and it still looks like 5ppm, I change all the water.

If you are wanting to cycle the tank for a capacity of 2 ppm per day of ammonia, increase the daily ammonia dose to 2 ppm again after the nitrite spike ends, to make sure it can process that much to nitrate in a day.

[vidocha]

I wanted to provide an update after following DJW's advice. I ended up doing 100% water changes twice, because my first BB was consuming 2 ppm of ammonia within a day. At this rate I feel like it would have taken another 2-3 months before my nitrites went down, instead it only took me another 2 weeks.

I'll include what I did, in case it'll be helpful to anyone in the future, especially newbies like me:

1. Make sure your 1st BB colony is large enough that they are consuming at least 2ppm of ammonia within close to a day.
2. Extremely dilute your nitrite water tests (for API Master test, I added 1-5 drops of aquarium water, and the rest tap water)
3. If you're still reading high nitrites, your nitrites are exponentially off the charts and I recommend changing your water.
4. Let your ammonia fall back to 0, then add ammonia back into the tank. I added a little extra (1.5x) to make sure the BB will have a good last super
5. Once your ammonia reads 0ppm again, remove all the water from your tank.
6. Once the tank is empty, add 5 gallons of water, and remove that too to get all of it.
6. Leave the aquarium water in your filter, in my case a HOB. The nitrites in that little bit of water was enough to read 5ppm of nitrites at the end!
7. Add fresh water back to your tank, that is close to your original temperature. Also, add conditioner (Prime) to your new water.
8. Once you're done, do a water test, the Nitrites should still be high.
9. Do not add ammonia for the next 2-3 days, this will give your 2nd BB a head start on consuming the nitrites.
10. After 2-3 days, add your normal amount of ammonia back to your aquarium.
11. Wait 1-3 weeks, if needed repeat the process.

As per the usual, every situation is different, and you might not get the same results. Once my tank was cycled, I went to my LFS to test water hardness. The manager rolled her eyes when I told her I did this, and she guaranteed I destroyed my cycle. Sure enough, after she tested my water, I had 0ppm for ammonia and nitrites. I feel that if I didn't do this process, I would still be stuck in a Nitrite spike, resulting in the dreaded months of waiting for the cycle to finish.

[bluelagoon]

It will usually take about 4-6 weeks no matter what method is used.Just curious,what are the nitrates reading now?

[vidocha]

It will usually take about 4-6 weeks no matter what method is used.Just curious,what are the nitrates reading now?

It's been 4 days since I stocked my tank, and nitrates reading 0ppm. Hopefully what I did avoided months of waiting.

Regardless, I am just happy the fish are here. I've been waiting since early January, and had to restart halfway through because I switched out filters.

[JamesW]

Your BB doesn't disappear with a water change. It is in your filter media. As Snap said high NH3 or NO2 can inhibit growth of the bacteria that consumes it. Generally NH3 should be kept below 5 ppm. I don't have a good number on Nitrites but it makes sense to keep it at least 'on chart' of the API test kit < 5ppm. Seachem Safe, API Quick Start and TSS can and do accelerate the fishless cycle when dosing with ammonia and nitrite levels are kept in check.