Fishless Cycling

[greenmumma141]

Thanks, I actually like reading up on this stuff and learning about it. I plan to just swap my entire cycled filter (running in the current tank now) and I am also purchasing a new filter as well so I will have two. I will take the cycled spnge and ceramics that have been in a ziploc and use those in the new filter, if i have any bacteria in them at all, it will be better than starting with a fresh sponge. ( plus the current filter, so I think I am more than set) Thanks again for the help and info.

 

[eaglesaquarium]

Thanks TTA.

First paragraph of conclusion section of the paper TTA linked to...

From this review it is clear that AOB possess several physiological traits that can be advantageous for their survival under conditions of variable substrate and oxygen supply. Moreover, AOB possess a number of enzymological and molecular mechanisms that allow them to maintain the state of their cells under starvation such that ammonia oxidation can start within minutes and at high rates after substrate or oxygen depletion. Furthermore, within the AOB groups, differences exist in adaptation to and competitiveness under conditions of high or low ammonia or oxygen concentrations. In addition, they seem to be able to communicate through cell-to-cell signalling and to move towards a more favourable environment.

AOB - Ammonia Oxidizing Bacteria

One thing I would point out, is that the factors that they were highlighting are generally things that we have no control over, specifically as fishkeepers. One such element is which strain of bacteria you have specifically in your tank:

In contrast, the regeneration time of strain G5-7 increased with increasing starvation time: after a starvation period of 1–2 weeks, the strain started to oxidize fresh ammonium almost immediately, but after 4 weeks of starvation, a lag period of several hours was observed, and after 10 weeks, 5 days were needed before ammonia oxidation started.

One other element that I noticed is that no where did they say what the drop off was concerning the ability to convert ammonia to nitrite or nitrate was. For example, if your sample of bacteria is converting 5ppm for a given tank in a 24 hour period prior to this starvation, they give no results that I saw (maybe I missed it) regarding the rate of conversion when it starts to convert. The conversion rate would be a major factor as well as the time it takes to happen, that would be very helpful to a fishkeeper. (This is stated in no way to disparage this work, but merely to point out the lack of information for "depending" on the reanimation of the AOB out of dormancy by any means available to a fishkeeper.)

 

[TwoTankAmin]

You are welcome, eagle.

First let me point out the the thing I would hope most folks take away from that paper is that it is clear that the bacteria do have ways to survive. Some may only be ok for a couple of weeks, other will be Ok for many months. But apply that range to our tanks and suddenly reading that the bacteria can only last for hours or that they die off at the rate of 10% a day should be more troublesome than whether our species are ones which only start to suffer after 2 weeks or ones that last a few months don't you think.

We do have control over the bacteria we select to a decent extent. And if certain strains enter the sytem, they will be the ones that eventually dominate the tank. This is what Dr. ovanec's research showed. But the way we exert control is by determining how much ammonia gets into the sytem during cycling. Then there is the issue of whether bacteria is brought in intentionally rather than by whater the water from the tap contains.,If you use media, plants, bottled bacteria etc. all introduce strains.

One reason you saw nothing about nitrite oxidizers is the paper is about AOB not NOB

The other thing is almost every statement they make in that paper is followed by a link(s) to the paper(s) that support the statment. Scroll down to the bottom and, if you have the pattience to count the references cited, my guess is 75-100 papers. I have read parts of a number of them as well. Here is a link to another paper which deals with that:

Starvation experiment.N. europaea and the ammonia oxidizer G5-7 were grown in 50 ml of HEPES-containing mineral salt medium in 100-ml Erlenmeyer flasks. The starvation period started when the ammonium had been completely consumed. The cells were starved for 1, 2, 4, and 10 weeks at 25°C in the medium. At the end of the starvation period, ammonium was added to an initial concentration of 5 mM, and NaOH was used to restore the pH to approximately 7.8 after starvation. The Erlenmeyer flasks were incubated on a shaker at 120 rpm and 25°C. Samples were taken, cells were spun down at 15,000 × g for 10 min, and the supernatant was analyzed for nitrite and nitrate. The growth rates were calculated via ln transformation of the nitrite (N. europaea) and nitrite-plus-nitrate (ammonia oxidizer G5-7) contents (2). All of the different starvation treatments were tested in four replicates.

From http/aem.asm.org/content/68/10/4751.full

And I could provide more links for other studies. But they would all support the same important fact. The various ammonia oxidizing bacteria survive adverse conditions and remain viable in some numbers even after periods of somewhere between weeks and months being deprived of a ammonia and oxygen depending on the strain.

Sometimes in fish keeping it can be important to dispel a mistaken piece of information even when we can't replace it with the exact correct answer.

 

[eaglesaquarium]

Thanks again TTA.

I do agree with your last statement, that's the nature of science. And dispelling myths, even if you don't have all of the correct information is just as valid, and sometimes more so.

One more thing that I didn't have a chance to ferret out of this was if the media was kept wet (submerged) the entire time, or is there something else regarding it being dried out?

 

[daizeUK]

And I could provide more links for other studies. But they would all support the same important fact. The various ammonia oxidizing bacteria survive adverse conditions and remain viable in some numbers even after periods of somewhere between weeks and months being deprived of a ammonia and oxygen depending on the strain.

The simple fact that a bare tank can theoretically be cycled with nothing but dechlorinated tap water seems to support this. It suggests that some of the bacteria must have survived in the chlorinated water supply under extremely adverse conditions.

 

[fluttermoth]

I have, for a long time now, thought it it's purely the reduction in numbers of bacteria present in the water supply that is the reason we have to cycle now when in the past nearly everyone (myself included) used to fish-in cycle quite happy; often (although I never did this) including washing filter media (mostly gravel from UGs) in raw tap water and not dechlorinating.

 

[TwoTankAmin]

I would be happy to provide links to research re questions/observations raised in the last 3 posts.

Eagle- I can link you to a study on nitrifying bacteria able to survive drying out. It regards soil bacteria stored for decades in dry conditions still being viable. Unfortunately, this one is only fee as an abstract.
Survival of bacterial DNA and culturable bacteria in archived soils from the Rothamsted Broadbalk experiment
http/www.sciencedi...038071707004683
The thing is the bacteria live in a biofilm. This protects them during dry periods for some amount of time. What appears dry to you and me nay bot be so dry if it has a biofilm. One needs to change the focus of ones investigation to biofilms in order to study this facet of things

daise- I can link you to studies regarding chlorine and chloramine treatment of drinking water. The most surprising thing is related to chloramine. This actually contributes to the growth of nirtifying bacteria. Durning tretament it causes the bacterial to go dormant and when the chloramine breaks down it produces ammonia which the bacteria use to revive and grow, I can also link you to research dealing with nitrifying bactria living in the pipes and plumbing on private property after the public water supply is no longer regualted as it is when it arrives at the point of private propert pipes. The first one is a 200 page Ph.D. thesis, but the information is there.
Development and Use of Microelectrodes to Evaluate Nitrification within ChloraminatedDrinking Water System Biofilms, and the Effects of Phosphate as a Corrosion Inhibitor on Nitrifying Biofilm
http/etd.ohiolink....?ucin1258489526
Accelerated chloramine decay and microbial growth by nitrification in premise plumbing http/www.academy.l...se-plumbing.pdf

flutter- I would actually arue the opposite. In the old days chlorine was favored over water in drinking water treatment. It is slower to penetrate the bio-film but once there is a more effective killer. Now with so many plants using chloramine, they are killing more of the other bacteria but the side effect is it is creating much more ntfyining bacteria in the system. The two above papers will suport that. However, chlorine penetrates the biofilm at a significantly slower rate than chloramine. So washing the gravel in chlorinated tap water does give it sufficient exposure to a high enough concentration to do serious harm to established nitfiers linving in a biofilm. Soaking it overnight would be another matter.

 

[daizeUK]

I'm still skimming through the papers but there's a few things in your last paragraph I didn't understand. I've corrected a couple of statements that I thought you might have mistyped, if I have misunderstood and got it wrong then please correct me.

flutter- I would actually arue the opposite. In the old days chlorine was favored over water chloramine in drinking water treatment. It is slower to penetrate the bio-film but once there is a more effective killer. Now with so many plants using chloramine, they are killing more of the other bacteria but the side effect is it is creating much more ntfyining bacteria in the system. The two above papers will suport that. However, chlorine penetrates the biofilm at a significantly slower rate than chloramine. So washing the gravel in chlorinated tap water does doesn't give it sufficient exposure to a high enough concentration to do serious harm to established nitfiers linving in a biofilm. Soaking it overnight would be another matter.

Let me see if I have understood this correctly.
Chloramine is unstable and eventually degrades to create ammonia. This promotes AOB nitrifier growth which feed on the ammonia.
The AOB nitrifiers then produce nitrite, which creates chlorine demand... meaning that it reacts with the chloramine to break it down and so chloramine is removed from the system.
However chloramine itself is still a biocide which destroys bacterial cells including our beloved nitrifiers, therefore in your example of washing gravel shouldn't this still have an generally detrimental effect?

Edit: I found my answer in part 5 of the thesis and see what you mean, the chloramine was found to temporarily deactivate the AOB but not kill them, although they took about a week to recover fully. I guess this means that accidentally washing your filter media in tapwater isn't all bad, it may cause an ammonia spike but the bacteria will mostly survive.

 

[eaglesaquarium]

I believe what he is referring to is the amount of time required for it to bust through the biofilm. Chlorine is slower, but more toxic once it does. Chloramine is faster, but less toxic to the nitrifiers, because it can break down the molecule into chlorine and ammonium, which the bacteria can use to survive. So, I guess the point is the chloramine is more effective against OTHER bacteria, rather than AOB, which would explain why the ammonia part of the fishless cycle works so quickly. There are many more of the AOB bacteria, because they can survive the chloramines better than other bacteria. Which I suppose would indicate that the NOB (Nitrite Oxidizing Bacteria) are less abundant at first and take some time to build up their biofilm, etc.

Is that accurate?

 

[TwoTankAmin]

Yes- sorry I typed too fast and didn't check- I am coming down with something and am under the weather.

Chloramine kills a lot of the other nasty bacteria. The nitrifiers it basically puts to sleep. Once the chloramine breaks down there is a supply of ammonia which the bacteria "wake up' for and consime. The chloramine naturally breaks down, the nitrifiers have nothing to do with that. The end result is usually a problem with nitrates for the water companies.

 

[strobe1980]

Hi,my tap Ph is 7.6 and my tank Ph at the start of my cycle was 7.6 I'm now 11 days in and I did a high range Ph test and it's showinformation 8.0! Is this possible? Would it be cause there hasn't been a water change? I know a Ph range of 7.0-8.0 whist cycling is preferred but I'm worried that this will happen once my cycle is complete.

 

[eaglesaquarium]

Actually, the preferred pH is closer to 8.4, so there's no worry with that. Some people actually add baking soda (sodium bicarbonate) to their tank during a fishless cycle to keep the pH up - not only does it raise the pH, it raises the kH which helps keep the pH more consistent, which is also important for the cycling process.

 

[strobe1980]

I was advised on using bicarb by lock man,my main question is, is this rise in Ph due to the tank cycling and lack of water changes and is this something to worry about once I have added my fish,I want to keep adolfi corys, flyweight tetras and maybe 2 apisto borelli or dwarf gourami. Is this just a fluctuation,it is only a 60ltr tank so African cichlids are out the question.

 

[eaglesaquarium]

I believe it may be due to the addition of the ammonia, which is usually added as ammonium hydroxide (which has a pH over 7, and can bring the pH up).

Did you test the pH with the high pH kit before starting the cycle as well?


Another possibility is that you might have some issues with something in the substrate that is messing with the pH. What is your substrate? What else is in your tank? You can lower the pH by adding driftwood and other organics which will help to take care of that issue, if needed.

 

[strobe1980]

I did teat with high ph and it was the lowest on the chart,7.4.i have pettex premium aquarium gravel?