My Cycle Data

[hakova]

After consulting with some members via PMs, I decided that I was misinterpreting the nitrite readings. It was actually off the chart when I thought it was zero; some kind of color blindness I guess . Here is a picture comparing my tank's reading on the left, to the tap water reading (actual zero) on the right:

The 5 drops you add to the 5 ml tank water from API kit nitrite bottle also act differently when it is zero vs. off the chart. If it is off the chart, the drops assume a deep purple color as they sink to the bottom of the tube then convert to a turquoise color at the end of five minutes, whereas if the actual level is zero, they assume a blue color at the bottom and remain as the same color at the end of the 5 minutes. The picture above was taken at the end of the five minutes.

I hope this helps to prevent confusion in other novice members. I updated my cycling data at google docs. Now it reflects the real values. The unfortunate thing is that I have already ordered the plants, now I need to continue cycling with the plants in, and probably face the algae problem .

 

[waterdrop]

Hi hakova,

Sorry I was not more help with this at the time. When I was first learning about the API kits here on TFF I remember we had a number of posts warning about how you can get fooled by the turquoise thing. Your picture there is a good comparison. Sorry it got you on the wrong schedule with your plants. I'd start with only 4 hours of light to help the process of avoiding algae!

~~waterdrop~~

 

[hakova]

No need to apologize waterdrop,

1. No harm is done so far.
2. I was able to put a hold on my order for plants, so now I can continue my fishless, plantless cycle in the dark .

I really think we should come up with some sticky note in the beginners section to warn the beginners about this potential problem though. What do you think would be the best route to pursue this? PM a moderator?

 

[waterdrop]

Yeah, we 'awta add a paragraph somewhere in one of our "detail" articles in the BRC

 

[hakova]

Hi there,

Just wanted to add an update to my cycling diary. Looks like with the falling pH a water change is impending. I will probably wait another day though before doing that.

Is it only the rising nitrates that cause the pH drop, or rising nitrites also have a similar effect? In my case, it looks like the latter. I will be a very happy guy the day I see nitrate level >5 ppm.

Thanks for reading.

 

[waterdrop]

I believe its just the nitrates. When we say nitrates we are talking about molecular stuctures that are ions and exist in an equilibrium in several states when dissolved in water. I think normally you'd find about 93% really being a nitrate ion and about 7% being nitric acid and its that 7% of the "nitrate" that's sending the pH down, nitric acid being a strong acid. Somebody actively doing chem will probably come along and shoot down the way I said that, lol.

~~waterdrop~~

 

[Rediahs]

Wow, nitrites up over 100!!!

I am pretty new at this, but in my fishless cycle, I had very very high nitrites, not sure how high.... I had that turquoise colour in the tube, and drops that turned purple as soon as they hit the bottom. Was recommended that a water change might help and that high nitrites can stall the cycle.

After I did my water change I found that I was much closer to being cycled than I had thought. My nitrites were coming to zero in 24 hours after I changed the water.

You could do a 90% water change and see what happens?

 

[hakova]

Thanks for the replies guys. Let me explain the details how I came up with nitrite level of 100. First I counted the drops in 5 mls. That gave me an idea how many ml a single drop was; 0.1 ml in my case. Then I used a 15 ml tube that had markings at every ml, filling it up to 9 ml with tap water, which I knew had zero nitrite. Then I added 9 drops of tap water and 1 drop of tank water, making it a total of 10 mls. Then I shook the tube to mix them well, and got 5 ml out of it to measure the nitrite level, which was 1 ppm (I think, because the drops did not turn to purple immediately as they hit the bottom, but the whole solution rather changed color within 5 minutes). Then of course I multiplied this with 100, since it was a 100x dilution of tank water.

I will do a water change tonight, probably a large percentage (90%). Hopefully it will be like in your case Chrissi, very close to complete cycling.

 

[waterdrop]

Yeah, actually that wonderful datasheet you've got helped me also to notice that this is the first time your pH has fallen into the 6's, so combined with the high nitrites and the fact that a weekend is upon us, its really a good time for you to do a 90% with good gravel cleaning (just for practice.. and because I sometimes think more nitrates hang out down in there anyway, clinging to the DOC/mulm type molecules somewhat..) and being sure to recharge ammonia(!)

Technically you don't really "need" a water change, and they -can- cause a day or so "pause" in the progress but as Chrissi observed in hers, often them seem to clear up the picture of what's going on and seem to give the process a little kick pretty often. In fact, for your case, one of my feelings that's pretty strong is that the pH is the one thing that's a pretty steady ramp (a more predictable curve) having and effect on the speed of the process. Putting in fresh tap water of a higher pH should have a speed-up effect even if slight, and the fresh tap water also provides some more calcium and iron traces for the bacteria, which might be important although there've never been enough published papers to fully show that is my guess.

~~waterdrop~~

 

[mayurkirti]

everything in this thread sounds so much like what I am going through. My readings almost match what you are seeing right now. And I got confused by the nitrites test too, except I knew that if the drops turn purple at the bottom of test tube it means nitrites are off the chart no matter what color you get after waiting for 5 mins.

Good luck to you hakova! I know it would be great if the tanks cycled in just 2 weeks but very slim chance that it may actually happen.

 

[hakova]

Thanks a lot for the inputs, and thanks for your wish mayurkirti. I really wish this cycling would take shorter, too. Well, at least we don't have fish to worry about, yet. I will keep posting results and hopefully one day we will celebrate them altogether .

 

[hakova]

After the initial drop in nitrites following 80% WC, for the first time there is no up trend observed in nitrites. It may have even started decreasing! Link to my cycling diary.

I still have ways to go most probably but starting to get excited here .

 

[waterdrop]

 

[hakova]

Hi there,

I think things are OK at the moment. I have no problem with my A-bacs, which can convert 5 ppm ammonia to 0 ppm over 12 hours; however the N-bacs can still only handle ~6.25 ppm nitrite over 12 hours. I calculated this as follows:
AM nitrite level: 0.5 ppm. Ammonia added to raise the level to 2.5 ppm.
PM ammonia level: 0 ppm. Therefore, 2.5 ppm ammonia x 2.7 conversion factor = 6.75 ppm nitrite was formed in 12 hours.
PM nitrite level: 1 ppm. Therefore 6.75 - (1.0 - 0.5 ) = 6.25 ppm nitrite was converted by N-bac over 12 hours.

The other thing is I did a 50% WC last night because the pH was 6.0. I should have done a bigger WC I guess, because the pH is again 6.0 tonight! I also started my DIY CO2 system running as of this morning, I am sure it is contributing to the pH drop. I have some star moss in the tank now, so I started the light cycle with 4 hours a day and didn't want to do that without any CO2, to prevent promoting algae growth with all the light.

I know this probably still means that my tank needs further maturation . It is just too hard to stay patient after all those weeks. I will receive more plants on Friday, I just hope that they help me to decrease the need to change my water too often.

Edit: Edited the calculation above with correct numbers.

 

[hakova]

Well, perhaps I spoke too soon again. This morning I was surprised to see that not all the ammonia I put 12 hours ago was processed. The nitrites also showed the familiar pattern of going off the chart with purple sinking drops. Is this a shrinkage of bacterial colonies by something I did, or just a response to 80% WC?

• I did *not* forget to put water conditioner to the bucket with fresh tap water
• I cleaned the fine (white) sponge in the *old* tank water
• I did *not* let the filter substrate dry; as soon as I cleaned the sponge I submerged it in old tank water in the canister
• I dropped the temperature to 81F

The reason I did a second WC in 24 hours was because of the pH being 6.0. Right after the WC the pH only rose to 6.6. I retested my tap water, it is 7.2 (it was 7.6 about three weeks ago). I switched the outlet of CO2 system from an air stone to a powerhead, which is off all day but 4 hours when the lights turn on. This setting generates a large CO2 bubble floating up to tank surface every 5-10 seconds when the powerhead is off. Therefore, I don't think there is a lot of CO2 dissolving to decrease the pH.

I won't do another WC for a while probably, although the pH was already 6.0 as of this morning. Any recommendation, troubleshooting attempts will be very much appreciated.

Here, again is the link to my diary.