What did I do to my Nitrogen Cycle?

baileyjack

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A little over a month ago I bought a 45 gallon tank, seeded it with filter medium from another tank I own, and used cheese cloth to hang gravel from that same tank - currently doing a fishless cycle. Everything was going super smooth, and about 5 days ago I noticed my ammonia levels were at 0ppm, nitrites were at 0ppm and my nitrates were around 15ppm. I left the tank alone to make sure I wasn't messing with anything before it was fully ready, then yesterday I did my first water change (about 25-30%), and retested. My ammonia was still 0ppm, nitrites 0ppm and my nitrates were up to 40ppm.

So this brings me to today, I wanted to wait to give it time again because my nitrates are still too high, so I retested this morning and ammonia and nitrites were 0 but my nitrates spiked to 80ppm. After looking on a few forums I saw that people were recommending to do an 80% water change to get 80% of the nitrates down, so that's what I did. I did that about 5 hours ago and I just retested it, my ammonia is back up to 0.25ppm, nitrites 0ppm and now my nitrates are also 0ppm.

How did I manage to screw up my cycle so much? Am I just testing too soon after a water change? Or did I do too big of a water change and reck my bacteria?

I've never had ammonia come back after the tank has been cycled for so long, I was half expecting to do the large water change, have my nitrate levels come down and then start moving a few fish in this weekend but now I am scared that my tank just restarted the nitrogen cycle. Please help!
 

StarGirl15

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That is odd. Maybe it was too close to the water change. What is in there to make the nitrates go up?
 
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baileyjack

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StarGirl15 said:
That is odd. Maybe it was too close to the water change. What is in there to make the nitrates go up?
All I have in there is a rock, a few plastic decorations, some plants (an Anubis and some Heteranthera zosterifolia - I had to google that) - about 4 days ago I put in a piece of MopanI Driftwood in it. I had added a bit of fish food into it last week to try and speed up the process, but that doesn't explain why they spiked between yesterday and today??
 

StarGirl15

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Maybe the food took that long to rot and cause the ammonia?
 
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baileyjack

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StarGirl15 said:
Maybe the food took that long to rot and cause the ammonia?
Perhaps? Maybe when the did the 80% water change I stirred some of it up?

The ammonia level is low enough that I am not insanely concerned (I won't add fish yet), but the thing that scared me was that the nitrates went down to 0ppm. For it to go from 80ppm to 0ppm in one water change seems crazy to me, so I am scared that that bit of ammonia is showing up because I killed off all the bacteria that's been converting it to nitrates?

Do you think that's possible or do you think I am just back to my waiting game? I'm sad cause I thought that tank would be ready after the water change today.

JettsPapa said:
I wouldn't worry about 0.25 ppm ammonia as long as it doesn't go higher.
I'm scared because I'm just coming out of cycling this tank so I don't want to put fish in there if there is ammonia and not any nitrates. Do you think the nitrates will come back? Or should I try and bring up my ammonia levels and then retest tomorrow?
 

StarGirl15

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I would check it later and see whats up. Ive not shook the test bottles enough myself and got a bad reading.
 
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baileyjack

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StarGirl15 said:
I would check it later and see what's up. Ive not shook the test bottles enough myself and got a bad reading.
Thank you so much! I'll try again in a few hours and if its still not great I'll wait until tomorrow.
 

StarGirl15

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That Nitrate test is a tricky one for sure. It should be as easy as the rest!
 

cmid21

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baileyjack said:
A little over a month ago I bought a 45 gallon tank, seeded it with filter medium from another tank I own, and used cheese cloth to hang gravel from that same tank - currently doing a fishless cycle. Everything was going super smooth, and about 5 days ago I noticed my ammonia levels were at 0ppm, nitrites were at 0ppm and my nitrates were around 15ppm. I left the tank alone to make sure I wasn't messing with anything before it was fully ready, then yesterday I did my first water change (about 25-30%), and retested. My ammonia was still 0ppm, nitrites 0ppm and my nitrates were up to 40ppm.
I am very confused on the question here, so apologies if I misinterpreted. Please clarify if I am not understanding correctly. If your ammonia and nitrites go to a reading of 0 ppm after 24 hours of adding ammonia, then you are fully cycled. Nitrates mean nothing to the cycle, they are theoretically irrelevant in this regard.

baileyjack said:
So this brings me to today, I wanted to wait to give it time again because my nitrates are still too high, so I retested this morning and ammonia and nitrites were 0 but my nitrates spiked to 80ppm. After looking on a few forums I saw that people were recommending to do an 80% water change to get 80% of the nitrates down, so that's what I did. I did that about 5 hours ago and I just retested it, my ammonia is back up to 0.25ppm, nitrites 0ppm and now my nitrates are also 0ppm.

How did I manage to screw up my cycle so much? Am I just testing too soon after a water change? Or did I do too big of a water change and reck my bacteria?
Nitrates are only removed from the water through water changes and/or through plants as they will use nitrates. (plants also use ammonia and nitrites) It is just part of the process. It sounds like your cycle is good. Don't worry at all about nitrates when evaluating the nitrogen cycle. All this dictates is how often you will have to do a water change to remove them. The higher the reading, the more frequent water changes. Nitrates do not have to be 0ppm to be fully cycled. In fact they really are inconsequential to the process.

Before we conclude that your tank is fully cycled and ready for fish: Have you been adding ammonia of some sort through this cycling process? ("food" for the beneficial bacteria- nitrification process)
 
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baileyjack

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cmid21 said:
I am very confused on the question here, so apologies if I misinterpreted. Please clarify if I am not understanding correctly. If your ammonia and nitrites go to a reading of 0 ppm after 24 hours of adding ammonia, then you are fully cycled. Nitrates mean nothing to the cycle, they are theoretically irrelevant in this regard.


Nitrates are only removed from the water through water changes and/or through plants as they will use nitrates. (plants also use ammonia and nitrites) It is just part of the process. It sounds like your cycle is good. Don't worry at all about nitrates when evaluating the nitrogen cycle. All this dictates is how often you will have to do a water change to remove them. The higher the reading, the more frequent water changes. Nitrates do not have to be 0ppm to be fully cycled. In fact they really are inconsequential to the process.

Before we conclude that your tank is fully cycled and ready for fish: Have you been adding ammonia of some sort through this cycling process? ("food" for the beneficial bacteria- nitrification process)
Yes, that's what I had thought also. In order for me to add my fish though, I wanted my nitrates lower than the reading I was getting, so I did a water change to correct this. After the water change however, the ammonia levels came back and stayed back at 0.25 for 2 full days. So that means that something I did shocking the tank into some sort of mini cycle (I am assuming).

I retested my nitrates the next day and got a reading of 5ppm, but still with 0.25 ammonia. Yesterday was the first day since this that I tested and had no ammonia and today same thing, so now I believe the tank is fully cycled (no nitrites and 5ppm nitrates still). I had thought that my tank was fully cycled that's why I did the huge water change because then I was ready to get my nitrates down. I think I may have just messed something up with the cycle when I was doing that because then ammonia had come back. But now it seems to all be good and its staying relatively consistent.

I added some flakes, and on another day I added some frozen bloodworms too just to get the ammonia up, although it never really got higher than 2ppm.
 

StarGirl15

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Maybe get some regular ammonia. Easier to regulate than fish food
 

cmid21

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baileyjack said:
Yes, that's what I had thought also. In order for me to add my fish though, I wanted my nitrates lower than the reading I was getting, so I did a water change to correct this. After the water change however, the ammonia levels came back and stayed back at 0.25 for 2 full days. So that means that something I did shocking the tank into some sort of mini cycle (I am assuming).

I retested my nitrates the next day and got a reading of 5ppm, but still with 0.25 ammonia. Yesterday was the first day since this that I tested and had no ammonia and today same thing, so now I believe the tank is fully cycled (no nitrites and 5ppm nitrates still). I had thought that my tank was fully cycled that's why I did the huge water change because then I was ready to get my nitrates down. I think I may have just messed something up with the cycle when I was doing that because then ammonia had come back. But now it seems to all be good and its staying relatively consistent.

I added some flakes, and on another day I added some frozen bloodworms too just to get the ammonia up, although it never really got higher than 2ppm.
Doing a water change will not ruin a cycle. Either you went through a min-cycle as you suspected or you are getting inaccurate readings with your testing kit. (which is perfectly normal) As stated in a previous post, I would not worry if the ammonia test reads <.25ppm this could be caused by a multitude of factors. It sounds like you are good now. Good luck!
 

Hugooo

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Agreed with cmid21! I myself have had confusion about whether the ammonia is at 0 ppm or .25 ppm. Make sure to shake those bottles real good! ;)
 

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