Nitrogen Cycle

[PhishPhreek]

This subject keeps poping up all over the fishbox so I just figured we should have one place to go to cuss & discuss it.

nitrogen cycle   (thanks for the link Zulaab

I just love the way this graph peaks out the amonia at 2 weeks and the nitrites at 4 weeks.

I understand that the chlorine and clorimenes kill off all these bacteria in our drinking water.

STEP 1
The organic waistes breakdown into ammonia -
     Does this happen without the aid of bacteria ?
           IF bacteria is in a new tank before the fish are added will it die without and waste products ?
           Or will adding bacteria cause the waste products to break down faster causing a higer ammonia peak ?
     Will less fish waists result in less ammonia being produced and the ammonia spike to be delayed ?
STEP 2
The ammonia is converted to nitrites
    Will starting with only a few fish reduce the amount of amonia available and lengenthen the time it takes th cycle the tank ?
      IF bacteria is in a new tank before the ammonia is present will it die out before it can make nitrites?
      Will starting with a source of bacteria cause the ammonia to breakdown sooner and reduce the size of the nitriogen peak
    or reduce the time it takes to peak ?
STEP 3
The nitrites are converted to nitrates.
    Will starting with only a few fish reduce the amount of nitrites available and lengenthen the time it takes th cycle the tank ?
     IF bacteria is in a new tank before the nitrites are created will it dieout before it can make nitrates ?
     Will starting with a source of bacteria cause the nitrites to breakdown sooner and reduce the size of the nitrite peak
    or reduce the time it takes to peak ?

[nacra99]

Re: Nitrogen Cycle

Wow... that's a lot to think about on a monday morning....lol.
I think i'll start slow and just comment on step 1.

STEP 1 The organic waistes breakdown into ammonia -
     Does this happen without the aid of bacteria ?

Well... remember that most fish and inverts excrete ammonia straight up (as compared to uric acid - birds/reptiles and urea - mammals. So even without bacteria, there will be ammonia in the water as long as there are fish.
         

IF bacteria is in a new tank before the fish are added will it die without and waste products ?

Not too sure.. but I would expect so. I had the experience of adding bio-spira to my empty tank in anticipation of a fish shipment, but it got delayed a week. When i did a "cycle test" (adding some ammonia to the tank) a week later, i found that the tank was not cycled. So either i got a defective packet of bio-spira, or the bacteria died. [/quote]

will adding bacteria cause the waste products to break down faster causing a higer ammonia peak ?

Well... it seems here like the bacteria's function is analogous to enzymes...according to what i remember from P.Chem Class, I would expect this to be true but only if there is a higher concentration of ammonia available for the bacteria to process.

Will less fish waists result in less ammonia being produced and the ammonia spike to be delayed ?

This is not a straight forward question. Generally, YES. Which is why fishless cycles with a higher concentration of ammonia usually complete faster than traditional cycling with fish, which typically have a lower concentration of ammonia.

I used the term "Generally" because there are other contributing factors to the ammonia spike. The ammonia spike is not only determined by the amount of bacteria, but also the amount of nitrAtes. NitrAtes inhibit the action of nitrifying bacteria. (note in the graph that the ammonia peak coincides with the emergence of nitrAtes). The ammonia will peak when 1) the amount of bacteria reaches a critical point considering the limited ammonia concentration and 2) NitrAtes begin to inhibit the bacteria.
Note also that bacteria growth also depends on things like temperature. (generally higher temps give higher growth). All these conspire to create exceptions to the rule.

[finfan]

Re: Nitrogen Cycle

ok, just to make sure it makes sense, i started my tank on Aug. 19th, added fish right away, here are my readinds (using API master test kit) so far (blank means did not test that item)

          ammonia, nitrite, nitrate, low range ph, high range ph,

8/22     .25          1.00       9          7.6   (added the filter bag from old tank)

8/23     .25          1.00       10        7.6   (added plants)                        

8/24     0              .75                   7.6   (added bogwood, removed old filter bag)

8/25     0              .75                   7.6   (removed old filter bag)

8/26     0     ~.35 to .40                        (did 15% water change - 1 week)

8/27     0     ~.25 or less    0         7.6              7.8

this is telling me that the cycle should be over soon right?

ok can nitrate really go to 0? or did i just do a bad test?  

houston (galleria) tap water is what i have, is ph 7.8 too high for my tetra's? it seems like it would be, what is the natural way of reducing it?

[finfan]

Re: Nitrogen Cycle

o, forgot to mention, the temperature is usually between 76 (early morning) and 78 (most of the day) - i don't have a heater

not sure if that has any affect on anything!

[AK-71]

Re: Nitrogen Cycle

It's a quick cycle  :? . Ammonia at .25 for 4 days and gone? How did you do this? How many and what fish for how long? Any additives? Water  changes? Old filters?
From what I read on WWW and my very limmited experience takes ~ 3 weeks with much higher numbers.

[eklikewhoa]

Re: Nitrogen Cycle

Looks like seeded filter media was used which is probably the reason for the fast cycle.

The NitrAtes is probably still there but in a lower unmeasurable amount by the test kit. The water change and plants probably helped it too.

[finfan]

Re: Nitrogen Cycle

hopefully my readings are not wrong (i don't think they are)

well, at first i added 6 white clouds - they did not do well at all and perished within 24 hours :(

then i went back to the lfs that i got them from and they said they had at least 5 or 6 other people with established tanks that had the same problem with that batch of white clouds, so it was probably a combination of poor quality fish and not the best water conditions in my tank

so the lfs was very nice and offered to give me something else instead, so i got 5 glowlights and 2 black neons on 8/22, they still seem to be happy (keeping my fingers crossed), i moved my two old cardinals from my old tank (5.5 gal) to this one on 8/25

i have been feeding them twice a day (enough food that they can finish in ~2 minutes)

i think the main helper was the change overdue filter cartridge bag from my old tank (i did not clean it) that i put on top on my new filter bag and the water that went through the filter touched both bags (at least that is what i think)

no additives other than dechlorination and used some prime (4 drops for 4 gallons) for the 15% water change done yesterday

i want to monitor this another week and if the nitrite and ammonia reads 0 for three days at least, i will add about 7 cardinals, wait another week or so and then add 6 more cardinals

[AK-71]

Re: Nitrogen Cycle

The reason I ask - I have just started a 10gal tank to breed Blue Rams (wigglers should be out any time now), yesterday measured ammonia ~.25, it already had a sponge filter I ran in my old tank for a week(seeded?). Yesterday I took ~ 2weeks old "blue-white" pad from my AC filter and wrapped around sponge filter. This lunch had to do 50% WC (2.5<ammonia<0.5).

I am considering (besides daily 50% WC):
1. removing male and let fry to take the chances (would hate to loose such a beautiful fish)
2. taking "whisper60" filter and try to fit it into 10gal with almost no flow settings and felt-covered intake (have some from City Pets) I have AC70 and Whisper60 in my 55gal tank - one will do there for now
3. Take a bio-bag from it and cover all the sponge filter in it.

Sorry for hijacking the thread.
AK

[finfan]

Re: Nitrogen Cycle

this is still related to cycling so i think its related to the nitrogen cycle  

ok someone please tell me if ph of 7.8 is too high for my tetras and if there is a natural way to lower it, my bogwood seems to have had no affect!

[Zulaab]

Re: Nitrogen Cycle

In my experience I have found Tetra's will live in almost any water, but your best colors are produced when you can bring the water down to at least pH of 7 or less.  I would recommend if you wanting to push the pH down then look at some of the threads here planted tanks and the use of soil in the tank as that will bring the pH down naturally.  The use of rainwater helps a ton...  I simply take rainwater and filter it via a coffee filter, and add it to my SA tank.   They all love it.

[finfan]

Re: Nitrogen Cycle

thanks zulaab,

can you please explain how to use coffee filter and why it is necessary, i want to collect rain water but don't know how to use the coffee filter rain water

thanks

[Zulaab]

Re: Nitrogen Cycle

I filter the water so ensure that no large particle which falls in after the water has been sitting like a little bug or anything small...  It takes a little time to do and it does not stop microscopic items getting into the tank.  But since I only put the bucket out when it rains I attempt to filter the water prior to my change.  Later in life I would like to get a big 55g drum or something like that where I can store the water for more than a few days outside before I tip it over and start fresh.

[CichlidFan]

Re: Nitrogen Cycle

I really get excited about learning about something that puzzles me, like this NC. I sure wish I could get a handle on it better from these postings here on the box, yet the real juicy part or the main concept still eludes me for the most part.
I'll have to get together one day with one of you folks who can speak lamen fluently and maybe then I will finally grasp the entire meaning of the circle of life.

We'll see...... :?  :!:


CF

[Mzungu]

Re: Nitrogen Cycle

 I'll try my best when I see you next, CF, if that would help.  :)

GREAT article, thanks Z and PP. Haven't read the whole thing yet, but the first few paragraphs are really good. Here's a good break down, IMO:

In aquaria-speak, the ``nitrogen cycle'' (more precisely, the nitrification cycle) is the biological process that converts ammonia into other, relatively harmless nitrogen compounds. Fortunately, several species of bacteria do this conversion for us. Some species convert ammonia (NH3) to nitrite (N02-), while others convert nitrite to nitrate (NO3-). Thus, cycling the tank refers to the process of establishing bacterial colonies in the filter bed that convert ammonia -> nitrite -> nitrate.

[Anonapersona]

Re: Nitrogen Cycle

OK, several things to discuss here.

First, the readings posted for tests during your cycle may be incorrect since you used Prime which binds ammonia.... some tests show only "unbound" ammonia, others show total ammonia which includes bound + unbound. I think the two-part test will give total ammonia, but I cannot recall, you might check the details in the test kit instructions. Un-bound ammonia is what hurts fish, total ammonia is what is availalbe to plants and filter bacteria.

Second, the ammonia and the nitrates are used by plants (but not nitrites), and so it is also likely that the quick drop to zero on those two is correct (an nitrites will take longer).

Know that under good light, nitrates will easily go to zero and at that point your plants may be nitrogen-limited (depending on how much ammonia is around at the same time). At this point, the oterh nurtients that are available are not being used and so are available to algae.

As for the total numbers you see and how fast they spike and drop... with fewer fish, it would still take the same amount of time to cycle (I think) since the total volume of ammonia is less, you end up with less bacteria at the end point, but it takes just as long to establish them (about 40 days) What is controlling is that the presence of ammonia makes it hard for the nitrite processing bacteria to form, so the ammonia processing bacteria have to complete their job before the next group can really begin. As long as you don't change things in the middle, like adding extra food and/or extra fish, the balance should be reached in about 40 days -- assuming you don't "cheat" by adding plants or used filter media!

If you added the correct sort of bacteria to the tank with a fresh dechlorinated tankfull of water and fish, all at the same time.... like one does using BioSpira or transferring a fully functional filter to a new tank full of fresh water and stocked with fish, it ought to be a pretty mild process, nearly un-noticible. That'd mean that the instant ammonia was available, some was converted to nitrite and as soon as it was available it was converted to nitrate, so no bacteria has to starve or go dormant waiting on a meal.