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View Full Version : Fishless cycle day 26 - Quantum leap in nitrates



georgef
11-27-2002, 08:59 PM
NitrItes have been through the roof (5 ppm which is the max for my test kit) since day 17.

The biofilter has been able to process ammonia from 3 ppm to 0 ppm in 12 hours since day 23.

NitrAtes first registered on day 17 and rose very gradually since then. They seemed to stall at around 7 - 10 ppm on day 21 and stayed there through day 25.

Day 25:
Ammonia - 0 ppm (last NH3 added on day 24 to 1 ppm)
Nitrite - > 5 ppm
Nitrate - ~10 ppm

Day 26:
Ammonia - 0 ppm
Nitrite - > 5 ppm
Nitrate - 40 ppm :o

Added a touch of NH3 tonight to keep the nitrosomonas happy. I'll check nitrItes tomorrow. If they're still through the roof, I think I'll do a partial water change to lower them a bit and let the nitrobacter/nitrospira catch up a bit.

Two things I've noticed throughout the cycle:

1. The water was slightly cloudy through the first two weeks before any nitrItes showed up. The day after I got my first nitrIte reading, the water became crystal clear.

2. At around day 15, the water gradually began to develop a light grayish haze again as nitrItes began to build. Today, after the nitrAte spike, the water is again crystal clear. So noticeably clearer than yesterday that most people in the office remarked on how much clearer the water was today without being prompted.

Ralph
11-27-2002, 10:02 PM
Hey George, I feel like I've been going through this with you.

It's going just fine, the nitrates are a good sign. Don't do a water change and keep adding ammonia. When you get 0 ammonia and 0 nitrites after a few hours, do a major water change (90 - 100%) and then you are ready for fish!

11-27-2002, 10:05 PM
Everytime I hear about someone having a long fishless cycling time inevitably they are adding ammonia throughout the cycling period. I recommend you stop adding ammonia and your cycle will be complete in no time. There is no need to continually add ammonia, it only prolongs the cycling time.

Dave

Ralph
11-27-2002, 10:38 PM
I agree with you Dave if the fish load is going to be small. Your shortcut is for a partially cycled tank. A fully cycled tank is able to handle certain levels of ammonia by changing them to nitrates within a fixed amount of time. If someone is adding the ammonia and still getting nitrite readings the next day, the safest thing is to wait until it is able to completely process the ammonia. The worst case scenario is discus with fin rot.

ronrca
11-28-2002, 12:00 PM
I would actually recommend doing a water change especially since you have been adding ammonia regular.

Why? Well, the ammonia gets converted to nitrites rather quickly (bacteria multiply rates) and by continuously adding ammonia, the nitrites keep rising and rising with every drop. What happens is that the level of nitrite is so high that it will take a very long time to actually bring the nitrite level down (because ammonia is contantly being added). If you do wait, the nitrite bacteria culture will actually grow huge compared with the ammonia bacteria and later when you do introduce fish, the nitrite bacteria will die down.

My experience was exactly that when cycling my 90G. I waited 3 weeks for nitrite to come down and it did not even lower at all. I did cut back on ammonia and was adding every second day, half the amount that originally was added. After 3 weeks, I said screw it and did a water change, around 25% and the next day, the cycle was complete. I added quite a bit of ammonia to 'test' the cycle and the day after, 0 ammonia, 0 nitrite and got a nice reading of nitrates.

So, can you add too much ammonia? Yes, you can and it will prolong your cycle. By doing a water change after 2 weeks from when your nitrites peak should help and no, you do not get a half cycled tank. If unsure if you tank is cycled properly, add a little more ammonia to 'test' it. You may be surprised that it works! However, I would not do a water change if you are not getting any reading in nitrates. In this case where nitrates doubled, you know your nitrite bacteria are doing a wonderful job but not even a dent in nitrite level. Bacteria can be negatively affected by high nitrate levels I believe!

(I hope that makes sense) ;D

The 'math' behind it

Week 1
The ammonia multiplies around lets say 12 hours (I believe its closer to 8 though)! Therefore in the first week it will double 14x!

1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192!

Week 2
I believe that multiply rate is around 24 hours for nitrite bacteria therefore in a 3 week period, you will have the bacteria double 21 times.

1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536, 131072, 262144, 524288, 1048576!

So now you can see the difference in bacteria cultures. After the ammonia has dropped to zero, there is not much mutliplying going on because the food source is not constant. Another thing that was not considered is that nitrite bacteria starting multiplying when there is nitrite level therefore after a 3 week period, you will actually have more than 21x multiply rate!

georgef
11-28-2002, 01:01 PM
Thanks, Ralph, Dave, and Ron --

I have cut back the NH3 to every other day. Last night was the day to add ammonia so I added until I registered 3 ppm. This morning, about 15 hours later, ammonia is at 0 ppm so the nitrosomonas are very well established. NitrItes are still through the roof, though.

And yes, Ron, that makes perfect sense. I am going to do a 25% water change today to lower the NO2 levels since I am reading a decent amount of NO3. We'll see what everything looks like after the wc and then after sitting for 24 hours. I will not add NH3 again until tomorrow. It would appear that having no NH3 for a day has not significantly reduced the effectiveness of the nitrosomonas. My goal is to have a bioflter that can handle ~ 3 to 5 ppm NH3 to NO3 in 24 hours or less before adding any fish.

I have been reading the Skeptical Aquarist website, and someone had proposed a theory that high ammonia levels may hinder the development of nitrobater/nitrospira. Interesting, seeing as how my NO3 did not signficantly rise until I cut back on the ammonia to every other day when the water was virtually ammonia-free for about 36 hours at a time. Hmmmm... :)

I'm actually tickled that the tank is at least well on its way to being cycled in less than four weeks. Especially considering that I did not seed the tank with anything. I've also found the process to be enjoyable, free of the stress of worrying about the health of my fish, and quite interesting.