Fishless Cycle Log

[Diesel Trout]

Hi all,

I am nearly two weeks into my fishless cycle so I decided to start this log now that I am seeing some results.

<u>Background/u>

I have a 72 gallon bowfront with Fluval 404 (bottom tray: pre-filter, middle bottom: carbon, middle top: biomax, top: biomax). The water outlet is above the water surface so there is lots of oxygen bubbles introduced into the tank. The temperature is set at 29 C. I am using black flourite sand, currently without plants (to be added later).

<u>Initial stats/u> pH: 7.6, water hardness = soft, ammonia: 0.0

The ammonia bottle did not specify a percentage so I used the base calculator which told me to add 15 ml (i.e. 1 tablespoon). This brought the ammonia level to 1.2 so I added another 15 ml. Near as I could tell this brought it to around 4-5 ppm.

<u>Day 1</u>
ammonia: 4-5 ppm

<u>Day 2 - 7</u>
stats are all the same (only testing for ammonia and pH up to this point).

At this point I added a mature carbon insert from my Aquaclear 20 (I stuck it in with the Fluval carbon).

<u>Day 8 and 9</u>
ammonia: 4-5 ppm
pH: 7.8

<u>Day 10</u>
ammonia: 2-3 ppm (it's dropping!)
NO2: 1 ppm (started testing now)
NO3: need new kit
pH: 7.8

<u>Day 11</u>
ammonia: 1.2 ppm
NO2: 1.6 ppm
NO3: 5 ppm
pH: 7.8

<u>Day 12 (today, July 24)</u>
ammonia: 0.6 ppm
NO2: 1.6 ppm
NO3: 5 ppm
pH: 7.8

It seems things are moving along!

<u>Day 13</u>
ammonia: 0 -> added ammonia: 4-5 ppm
NO2: 1.6
NO3: 10
pH: 7.8

<u>Day 14</u>
ammonia: 4 ppm
NO2: 1.6 (looks a little darker than 1.6 but not quite 3.3)
NO3: 10
pH: 7.8

<u>Day 15</u>
ammonia: 0 -> added ammonia: 4-5 ppm
NO2: 1.6-2.5?
NO3: 5
pH: 7.8

<u>Day 16</u>
ammonia: 0 <img src="http/www.fishforums.net/public/style_emoticons/<#EMO_DIR#>/thumbs-up.gif" style="vertical-align:middle" emoid="" border="0" alt="thumbs-up.gif" />
NO2: 1.6-2.5
NO3: 5
pH: 7.6 (dropped a tad)

-> added ammonia...I think I finally got the amount right this time: 5 ppm

<u>Day 17</u>
ammonia: 0 -> added ammonia: 5 ppm
NO2: 1.6
NO3: 5
pH: 7.6

<u>Day 18</u>
7:00 am -> ammonia check: 0.6 ppm

9:00 pm
ammonia: 0 -> added 5 ppm
NO2: 1.6
NO3: NOT TESTED
pH: 7.0 (dropping!)

<u>Day 19</u>
7:00 am -> ammonia check: 0.65 ppm

7:00 pm
ammonia: 0 -> added 5 ppm
NO2: 1.6
NO3: 5-10
pH: 6.8


<u>Day 20</u>
9:00 am -> ammonia: 1.2
NO2: 1.6
pH: 6.6 - 6.8?

4:00 pm -> 50% water change to increase KH

7:30 pm
ammonia: 0
NO2: 1.6
NO3: 5-10
pH: 7.0

<u>Day 21</u>
<i>Added 1 tbsp of baking soda which raised the pH to around 7.2-7.4. I added another tbsp which resulted in pH=7.6-7.8 and KH took 7-8 drops to neutralize.</i>

7:00 pm
ammonia: 0
NO2: 1.6
NO3: 5-10

added ammonia 5 ppm

<u>Day 22 - bought a new test kit</u>
ammonia: 0
NO2: see photos below
NO3: still 5-10
pH: 7.8

<u>Day 23 - Nothing New</u>
ammonia: 0 -> topped up ammonia to 4 ppm. Yawwwn.
NO2: 1.0
NO3: 5-10
pH: 7.8

<u>Days 24 and 25</u>
ammonia: 0 -> added 4 ppm ammonia
NO2: 1-5
NO3: 5-10
pH: 7.8-7.4

<u>Days 26 and 27</u>
ammonia: 0 -> added 4 ppm ammonia
NO2: high
NO3: 5-10, 80 on day 27!
pH: 7.0

<u>Day 28</u>
<i>Added about 1.5 tbsps of baking soda.</i>
ammonia: 0 -> added 2 ppm ammonia
NO3: 80
pH: 7.8

<u>Day 29</u>
ammonia: 0
NO2: 0 <img src="http/www.fishforums.net/style_emoticons/<#EMO_DIR#>/yahoo.gif" style="vertical-align:middle" emoid="" border="0" alt="yahoo.gif" />
NO3: 80
pH: 7.8

-> added a bit more ammonia than day 28 (2-3 ppm)

<u>Day 30</u>
ammonia: 0 -> upped the ammonia to 4 ppm
NO2: 0

<u>Day 31</u>
7:00 am check: ammonia: 1.0 and NO2 still purple.

7:00 pm check:
ammonia: 0
NO2: 0

<u>Days 32 and 33</u>
ammonia: 0 -> added 4 ppm
NO2: 0

<u>Day 34</u>
9:00 am check: ammonia: 1.0 and NO2: 1.0
11:00 am added 1 tbsp of baking soda -> pH: 7.4
12:00 pm check: ammonia:0.5 and NO2: 1.0
7:00 pm no tests.

<u>Day 35</u>
9:00 am check: ammonia: 1.0 NO2: 1.0
3-5:00 pm changed 50% water and added plants
7:00 pm
ammonia: 0
NO2: 0
NO3: still 80
pH: 7.4

-> added 4 ppm ammonia

<u>Day 36</u>
8:30 am check: ammonia: 1.0 and NO2: 0.25

8:00 pm
ammonia: 0 -> added 4 ppm ammonia
NO2: 0
NO3: 80
pH: 7.2

<u>Day 37</u>
8:30 am check: ammonia: 1.0 and NO2: 0.25 - 0.50

7:30 pm
NO3: 80
pH: 7.0
-> added 4 ppm ammonia

<u>Day 38</u>
8:30 am check: ammonia: 1.5 and NO2: 0.75

Performed 50% water change, removed rotting cabomba <img src="http/www.fishforums.net/style_emoticons/<#EMO_DIR#>/angry.gif" style="vertical-align:middle" emoid="" border="0" alt="angry.gif" /> , added 1 tbsp baking soda

8:00 pm
ammonia: 0 -> added 4 ppm ammonia
NO2: 0
NO3: still 80
pH: 7.4

<u>Day 39</u>
8:30 am check: ammonia: 1.0 and NO2: 0-0.25

8:00 pm
pH: 7.4
-> added 4 ppm ammonia

<u>Day 40</u>
8:30 am check: ammonia: 2.0 and NO2: 0-0.25

5:00 pm: changed 50% water, rinsed foam in tank water, removed original mature media, added ferts

8:00 pm
ammonia: 1.0 -> added 2 ppm ammonia
NO2: 0
NO3: 40
pH: 7.4

<u>Day 41</u>
8:30 am check: ammonia: 1.0 and NO2: 0

8:00 pm -> added 4 ppm ammonia (no time for any tests due to <img src="http/www.fishforums.net/style_emoticons/<#EMO_DIR#>/drunk.gif" style="vertical-align:middle" emoid="" border="0" alt="drunk.gif" /> )

<u>Day 42</u>
9:00 am check: ammonia 2.0 and NO2: 0

8:00 pm
ammonia: 1-2 <img src="http/www.fishforums.net/style_emoticons/<#EMO_DIR#>/angry.gif" style="vertical-align:middle" emoid="" border="0" alt="angry.gif" />
NO2: 0
NO3: 80
pH: 7.4

-> did not add any more ammonia

<u>Day 43</u>
9:00 am check: ammonia: 1.0 and NO2: 0
added ferts and baking soda

8:00 pm
ammonia: 0.5
pH: 7.8

-> did not add any more ammonia

<u>Day 44</u>
9:00 am check: ammonia: 0.25

8:00 pm: ammonia and NO2: 0 -> added 4 ppm ammonia

<u>Day 45</u>
8:30 am check: ammonia: 2.0 and NO2: 0-0.25

8:00pm
ammonia: 1.0
NO2: 0
NO3: high
pH: 7.8

-> did not add any more ammonia

<u>Day 46</u>
8:30 am check: ammonia: 0.5 and NO2: 0

8:00pm
ammonia: 0 and NO2: 0 -> added 4 ppm ammonia

<u>Day 47</u>
8:30 am check: ammonia: 2.0 and NO2: 0.25

8:00 pm
ammonia: 1.0
NO2: 0.25

-> did not add any more ammonia

<u>Day 48</u>
9:00 am check: ammonia: 0.25 and NO2: 0.25

8:00pm
ammonia: 0 and NO2: 0 -> added 4 ppm ammonia

-> also added API root tab for Sword plants

<u>Day 49</u>
8:30 am check: ammonia: 2.0 and NO2: 0.5

50% water change, trace ferts

8:00 pm
ammonia: 0.5 -> did not add any more ammonia
NO2: 0.25
NO3: 40

<u>Day 50</u>
8:30 am check: ammonia: 0 and NO2: 0

8:00 pm added 4 ppm ammonia

<u>Day 51</u>
8:30 am check: ammonia: 2.0 and NO2: 0.25

8:00 pm
ammonia: 1.0 -> did not add any more ammonia
NO2: 0.25
pH: 7.4 -> added 1 tbsp baking soda

<u>Day 52</u>
8:30 am check: ammonia: 0 and NO2: 0 and pH: 7.9

8:00 pm added 4 ppm ammonia

<u>Day 53</u>
9:00 am check: ammonia: 2.0 and NO2: 0.25

added trace ferts

8:00 pm
ammonia: 1.0 -> did not add any more ammonia
NO2: 0.25

<u>Day 54</u>
8:30 am check: ammonia: 0 and NO2: 0

8:00 pm added 4 ppm ammonia

<u>Day 55</u>
9:00 am check: ammonia: 2.0 and NO2: 0.5

8:00 pm
ammonia: 1.0 -> did not add any more ammonia
NO2: 0.25
pH: 7.8

<u>Day 56</u>
8:00 am check: ammonia: 0 and NO2: 0

8:00 pm added 4 ppm ammonia

<u>Day 57</u>
8:00 am check: ammonia: 1.5 and NO2: 0.5

50% water change, trace ferts, installed Hydor heater.

7:00 pm
ammonia: 0 -> added 4 ppm ammonia
NO2: 0

<u>Day 58</u>
7:00 am check: ammonia: 1.5 and NO2: 0.5

7:00 pm
ammonia: 1.0 -> did not add any more ammonia
NO2: 0.25

<u>Day 59</u>
7:00 am check: ammonia: 0 and NO2: 0

7:00 pm
pH= 7.9
-> added 4 ppm ammonia

<u>Day 60</u>
7:00 pm
ammonia: 0 -> added 4 ppm ammonia
NO2: 0.5

Green algae is starting to develop.

<u>Day 61</u>
8:30 pm
ammonia: 0 -> added 4 ppm ammonia, added trace ferts
NO2: 0.25

<u>Day 62</u>
8:00 pm
ammonia: 0 -> added 4 ppm ammonia
NO2: 0.25

<u>Day 63 (week 9)</u>
7:00 pm
ammonia: 0.5
NO2: 0.25
pH: 7.4 -> add 1 tbsp baking soda

-> did not add any more ammonia

<u>Day 64</u>
7:00 pm
ammonia: 0 -> added 4 ppm ammonia
NO2: 0

<u>Day 65</u>
7:00 pm
ammonia: 0 -> did 20% water change to suck up some algae; added 4 ppm ammonia
NO2: 0

<u>Day 66</u>
7:00 pm
ammonia: 0.5 -> added about 2.5 ppm ammonia
NO2: 0.25

<u>Day 67</u>
7:00 pm
ammonia: 0.25 -> added about 4 ppm ammonia
NO2: 0
<u>
Day 68</u>
7:30 pm
ammonia: 1.0 -> did not add any more ammonia
NO2: 0
<u>
Day 69</u>
No tests done. Added 4 ppm ammonia

<u>Day 70 (Week 10)</u>
7:30 pm
ammonia: 1.0 -> did not add any more ammonia <img src="http/www.fishforums.net/style_emoticons/<#EMO_DIR#>/angry.gif" style="vertical-align:middle" emoid="" border="0" alt="angry.gif" />
NO2: 0
<u>
Day 71</u>
7:00 pm
ammonia: 0 -> added about 4 ppm ammonia
NO2: 0
NO3: Cherry Red
pH: 7.0 -> added 1 tbsp baking soda

<u>Day 72</u>
50% water change, Flourish ferts added.
8:00 pm
ammonia: 0.25 -> added about 4 ppm ammonia
NO2: 0
NO3: same colour as before water change
pH: 7.4

<u>Day 73</u>
7:00 pm
ammonia: 1.0 -> did not add any more ammonia
NO2: 0
-> added 1 tbsp baking soda

<u>Day 74</u>
7:00 pm
pH: 7.9
-> added 4 ppm ammonia

<u>Day 75</u>
7:00 pm
ammonia: 1.0 -> did not add any more ammonia
NO2: 0

<u>Day 76</u>
No tests. Added 4 ppm ammonia and Flourish.

<u>Day 77 (Week 11)</u>
7:00 pm
ammonia: 1.0 -> did not add any more ammonia
NO2: 0

<u>Day 78</u>
50% water change, added 4 ppm ammonia and Flourish.
pH: 7.8

<u>Day 79</u>
Received Seachem plant fertilizers. Added NPK and Excel.

7:00 pm
ammonia: 1.0 -> did not add any more ammonia
NO2: 0
NO3: 20ish? (more orange than red).

<u>Day 80</u>
No tests. Added 4 ppm ammonia.

<u>Day 81</u>
7:00 pm
ammonia: 0 -> added 4 ppm ammonia
NO2: 1.0 <img src="http/www.fishforums.net/style_emoticons/<#EMO_DIR#>/sad.gif" style="vertical-align:middle" emoid="" border="0" alt="sad.gif" />
pH: 6.8 crash! -> added 2 tbsp baking soda
-> water a bit cloudy.

<u>Day 82</u>
7:30pm
ammonia: 0 -> added 4 ppm ammonia
NO2: <b>5.0</b>
pH: 7.4 -> added 1 tbsp baking soda
put in some ferts.

<u>Day 83</u>
67% water change. Recharged ferts per Seachem's Day 1 schedule.

7:30 pm
ammonia: 0 -> added 4 ppm ammonia
NO2: 1.0
pH: 7.4 -> added 1 tbsp baking soda.

<u>Day 84 WEEK 12</u>
9:00 pm (forgot to do measurements!)
ammonia: 0 -> added 4 ppm ammonia
NO2: 0.25
pH: 7.4 -> added 1 tbsp baking soda.

<u>Day 85</u>
7:30 pm
ammonia: 0 -> added 4 ppm ammonia
NO2: <b>5.0</b>
pH: 7.4 -> added 1 tbsp baking soda.

<u>Day 86</u>
7:00 pm
ammonia: 0 -> added 4 ppm ammonia
NO2: <b>5.0</b>
pH: 7.8 -> added some baking soda.

<u>Day 87</u>
7:00 pm
ammonia: 0 -> added 4 ppm ammonia
NO2: <b>5.0</b>
pH: 7.8

<u>Day 88</u>
7:00 pm
ammonia: 0 -> added 4 ppm ammonia
NO2: <b>5.0</b>
pH: 7.8

<u>Day 89</u>
7:00 pm
ammonia: 0 -> added 4 ppm ammonia
NO2: <b>5.0</b>
pH: 7.8

<u>Day 90</u>
7:00 pm
ammonia: 0 -> added 4 ppm ammonia
NO2: <b>5.0</b>
pH: 7.8

<u>Day 91 (Week 13!)</u>
7:00 pm
ammonia: 0 -> added 4 ppm ammonia
NO2: <b>5.0</b>
pH: 7.8

<u>Day 92</u>
Performed 2/3 water change
7:30 pm
ammonia: 0 -> added 4 ppm ammonia
NO2: 0.25
pH: 7.4

<u>Day 93</u>
7:00 pm
ammonia: 0 -> added 4 ppm ammonia
NO2: 0
pH: 7.4 -> need to add some baking soda

<u>Day 94</u>
7:00 pm
ammonia: 0 -> added 4 ppm ammonia
NO2: 0
pH: 7.9

<u>Day 95</u>
7:00 pm
ammonia: 0 -> added 4 ppm ammonia
NO2: 0

<u>Day 96</u>
5:00 pm
ammonia: 0 -> added 4 ppm ammonia at 7:00 pm
NO2: 0
pH: 7.8

<u>Day 97</u>
9:00 am
ammonia: 0.25
NO2: 2.0

6:30 pm
ammonia: 0 -> added 4 ppm ammonia
NO2: 0

<u>Day 98 (Week 14!!!)</u>
7:00 pm
ammonia: 0 -> added 4 ppm ammonia
NO2: 0

<u>Day 99</u>
7:00 pm
ammonia: 0 -> added 4 ppm ammonia
NO2: 0

<u>Day 100</u>
7:00 pm - no tests done -> added 4 ppm ammonia

<u>Day 101</u>
7:00 pm
ammonia: 0 -> added 4 ppm ammonia
NO2: 0
pH: 7.8

Day 102
11:00 am
ammonia: 0 -> added 4 ppm ammonia at 7:00 pm
NO2: 0

Day 103
7:00 pm - no tests done -> added 4 ppm ammonia

Day 104
9:15 am -> ammonia: 0 NO2: 0.25
-> added 4 ppm ammonia at 7:30 pm

Day 105 - Week 15
8:15 am -> ammonia: 0 NO2: 0.25
7:00 pm -> added 4 ppm ammonia

Day 106
67% water change, fert day 1
-> added 4 ppm ammonia

Day 107
7:00 am -> ammonia 1.0 nitrite 0.50
7:00 pm -> pH: 7.8
-> added 4 ppm ammonia

Day 108
7:00 am -> ammonia 1.0 nitrite 0.25
7:00 pm -> pH: 7.8
-> added 4 ppm ammonia

Day 109
7:00 pm -> ammonia 0.0 nitrite 0.0 pH: 7.6
-> added 4 ppm ammonia

Day 110
7:00 pm -> ammonia 0.0 nitrite 0.0
-> added 4 ppm ammonia

Day 111
9:30 am -> ammonia 0.0 nitrite 0.5
9:15 pm -> ammonia 0.0 nitrite 0.0
-> added 4 ppm ammonia

Day 112 (Week 16)
8:30 am -> ammonia 0.0 nitrite 0.0!!!
50% Water change to clean up the tank. -> added 4 ppm ammonia

Day 113
7:00 am -> ammonia 0.0 nitrite 0.0

Day 114
7:00 am -> ammonia 0.0 nitrite 0.0
Small water change to clean up the tank. -> added 4 ppm ammonia

Day 115
7:00 am -> ammonia 0.0 nitrite 0.50
-> added 4 ppm ammonia

Day 116
7:00 am -> ammonia 0.0 nitrite 1.0
-> added 4 ppm ammonia

Day 117
7:00 am -> ammonia 0.0 nitrite 1.0
-> added 4 ppm ammonia

Day 118
8:30 am -> ammonia 0.0 nitrite 1.0
5:00 pm -> 50% water change, rinsed (2x) filter foam, removed (2nd) carbon, added more Biomax
7:30 pm -> added 4 ppm ammonia

Day 119 (Week 17)
8:00 am -> ammonia 0.0 nitrite infinity
7:00 pm -> nitrite 0.0 pH 7.2 -> add 1 tbsp baking soda and 4 ppm ammonia, added 10 caps Cycle

Day 120
7:00 am -> ammonia 0.0 nitrite 5.0 pH 7.8
7:00 pm -> added 4 ppm ammonia

Day 121
7:00 am -> ammonia 0.0 nitrite 5.0
7:00 pm -> added less than 4 ppm ammonia

Day 122
7:00 am -> ammonia 0.0 nitrite 0.0
7:00 pm -> added 4 ppm ammonia

Day 123
7:00 am -> ammonia 0.0 nitrite 0.25
7:00 pm -> added 4 ppm ammonia

Day 124
7:00 am -> ammonia 0.0 nitrite 0.25
7:00 pm -> added 4 ppm ammonia

Day 125
7:00 am -> no tests done
7:00 pm -> added 4 ppm ammonia

Day 126 (Week 18)
8:00 am -> ammonia 0.0 nitrite 0.25
7:00 pm -> added 4 ppm ammonia

Day 127
7:00 am -> ammonia 0.0 nitrite 0.25
7:00 pm -> added 4 ppm ammonia

Day 128
7:00 am -> ammonia 0.0 nitrite 0.50
7:00 pm -> added 4 ppm ammonia

Day 129
7:00 am -> no test done
7:00 pm -> added 4 ppm ammonia

Day 130
7:00 am -> ammonia 0.0 nitrite 0.25
7:00 pm -> added 4 ppm ammonia

Day 131
blah blah blah
7:00 pm -> 9:00 big water change and clean up

Day 132
FISH!!

 

[OldMan47]

You are doing fine DT. It looks like you have a very few ammonia processing bacteria starting to build in your tank and/or filter. So far we are not seeing the nitrite processors kick in but it is early for that yet.

 

[waterdrop]

yup, looks good to me too. -wd-

 

[Diesel Trout]

yup, looks good to me too. -wd-

Good stuff!

Days 13 and 14 are updated now.

Say, I noticed some fuzzy white filaments on my Malaysian bogwood. Are these friend or foe?

 

[waterdrop]

no worry, you get all sorts of strange stuff like fungus during cycling which eventually goes away or can be cleaned and will not come back later. -wd-

 

[Diesel Trout]

Day 15 updated.

Am surprised to see the ammonia drop back down to zero after two days. Also didn't expect the nitrates to decrease. Is this typical? Nitrites only increased marginally (somewhere between 1.6 and 3.3). Maybe I'm on the fast track!

 

[OldMan47]

Do you have any nice fast growing plants in that tank DT? They are good at removing ammonia and nitrates so they could be affecting your readings if you have them.

 

[Diesel Trout]

Do you have any nice fast growing plants in that tank DT? They are good at removing ammonia and nitrates so they could be affecting your readings if you have them.

No, haven't any plants in there yet. I think I may have misread the amount of ammonia I added on day 13 and didn't quite get it up to 4-5 ppm.

 

[OldMan47]

If you are seeing nitrates drop when you don't expect it, make sure you are shaking the bottles and tubes at least as long as recommended. I double the shaking times because good mixing is essential and you can't mix too well.

 

[Diesel Trout]

If you are seeing nitrates drop when you don't expect it, make sure you are shaking the bottles and tubes at least as long as recommended. I double the shaking times because good mixing is essential and you can't mix too well.

Day 16 updated.

Thanks OM47. This time I shook them like crazy and wore my watch. Still same outcome as previous day.

My ammonia has gone back down to zero and neither nitrites nor nitrates changed (nitrites might be a bit darker but def not dark purple (3.3). I upped the ammonia dosage a bit and for sure I now have 5 ppm. We'll see how the readings are tomorrow.

 

[Diesel Trout]

Day 17. Same readings as the day before. 5 ppm of ammonia being processed in 24 hours.

Should Nitrite and nitrate not be changing a bit? Nitrites seem to be holding steady at around 1.6 ppm...should I see an increase in nitrates soon as the new bacteria kicks in?

 

[OldMan47]

Either nitrites or nitrates should indeed be changing DT. If your nitrite processing bacteria have not yet developed, the nitrites would be rapidly rising and if they have developed they would be passing the nitrogen along as nitrates. Another possibility that I had not considered was that you might have some ion exchange resin or zeolites in your filter. If that is the case, you would see chemicals just magically disappearing and, unfortunately, the bacterial colonies night not be growing. In that situation, you will know when the zeolite or resin is exhausted because suddenly the ammonia will no longer process because the zeolite is exhausted and the bacteria will not be there to help. Unfortunately, if you believe everything that filter manufacturers tell you, you may have some of that stuff in your filter. The really unfortunate thing is that it means that you are on day 1 of your cycle when you remove the resin.

 

[Diesel Trout]

Either nitrites or nitrates should indeed be changing DT. If your nitrite processing bacteria have not yet developed, the nitrites would be rapidly rising and if they have developed they would be passing the nitrogen along as nitrates. Another possibility that I had not considered was that you might have some ion exchange resin or zeolites in your filter. If that is the case, you would see chemicals just magically disappearing and, unfortunately, the bacterial colonies night not be growing. In that situation, you will know when the zeolite or resin is exhausted because suddenly the ammonia will no longer process because the zeolite is exhausted and the bacteria will not be there to help. Unfortunately, if you believe everything that filter manufacturers tell you, you may have some of that stuff in your filter. The really unfortunate thing is that it means that you are on day 1 of your cycle when you remove the resin.

Days 18 and 19 are now update. My pH has come down from 7.8 to 6.8.

Wow OldMan, everything just went right over my head! If there are zeolites in there then I didn't add them! Where would they come from? Resins? Please explain.

 

[OldMan47]

It depends on the filter manufacturer. What they will do is give you filter media that says in large print it is to remove phosphates or ammonia or some other pollutant, but if you read the fine print on the package it will say that it contains a "scientifically chosen resin to remove xxxx". The problem is that ion exchange resin are not selective in what they remove. They will remove all ionic impurities from the water including ammonia, nitrites and even nitrates.
What stays absorbed depends on the ionic potential, usually listed by chemistry people as electronegativity. You could think of that as how well a particular ion is attracted to the resin. If you have resin exhausted to H+ and OH- to start with, you have what amounts to a new demineralizer resin, DI. Ions replace the H+ and OH- on the resin to release water, HOH, and both positive and negative ions are pulled from the water. Whatever first attaches to the resin can be similarly replaced by ions that are more attracted to the resin than that first ion was, you get an ion exchange at that point on the resin. In a perfect world, a resin that is being used to remove phosphate, for instance, will be carrying ions that won't have a negative impact on your tank and that are close to phosphates in their attraction to the resin. This would mean that they would release whatever they are carrying and absorb the phosphates. Unfortunately, resins are almost always regenerated using acids and bases or using salt like you would use in a home water softener. The salt regeneration replaces the metalic ion with sodium. The acid and base regenerations replace the metals with H+ ions and the non-metals with OH- ions. Where you end up is that everything that you add to the tank, such as ammonia, gets absorbed until the resin becomes exhausted to ammonia. At that point the ammonia absorption stops but other things can still be absorbed and release that ammonia back into the water by undergoing an ion exchange with something that is more attracted to the resin than the ammonia. It can give us weird looking results like you were seeing.

 

[Diesel Trout]

Thanks Mr. Science, that's exactly what I thought!

All the filter media I am using is Fluval. I have the foam, pre-filter, carbon (for now), and Biomax.

I did a water check this morning (see results above). A couple of observations about the results:

NO2 - upon shaking the tube after adding reagent #2 the colour immediately changes to the 1.6 ppm, there is no waiting 2 minutes for "the colour to develop".
pH - it lies somewhere between 6.6 and 6.8 (very difficult to discern between the two).

I also check KH this morning. First I checked tap water, dechlorinated with Aqua Plus water conditioner. It took 5 drops to change to yellow. Then I checked the water in the aquarium. It didn't even change blue when I added the first drop! I'm thinking I need to do a water change.

Please advise!