Cycling a new filter on a tank that’s already cycled

[castle]

I had a thought,

When cycling a tank we’re basically making a lot of denitrifying bacteria and others. From this point on, I’ll refer to all bacteria as bacteria. (Obv)

If bacteria in the tank is effectively limited by the amount of food going in, then if I add a second filter wouldn’t this filter only be taking a share of all available bacteria? If I’m only producing enough food for one canister, the other isn’t exactly going to be heavily populated, right?

When I was young I was told to always run two filters, and I’m guessing now there is some wisdom here. Two filters would likely mean a bacteria colony death in one filter may not wipe it out in both? But I guess that’s the only valid reason I’ve got right now.

If cycling a new filter on a pre-cycled tank, should I over feed for a couple of weeks to increase bacteria in the tank? Feels like that might be worth while?

Sorry, obviously a dumb thought process but I realise I have not given any thought to filtration (bacteria) in a long time, and as I’m setting up a reef tank at the moment, I was a bit like “hang on a mo”.

What’re your thoughts on this? (Ps, this post isn’t about plants, and their role in the aquarium 😉)

 

[Tim Harrison]

I think what’s important is a viable and species diverse inoculation community or colony. It’s not quantity that’s matters it’s quality.It’s like any community of organisms or any food web the more diverse the greater its robustness and stability and the greater its adaptability to environmental perturbations. And that’s likely to be the same in both filters regardless.

I’ve mentioned before generation times for nitrifying microorganisms are measure in hours and reproduction is by binary fission and therefore potentially exponential. So a species diverse colony will also rapidly adapt and grow to accommodate any environmental change. IME significant adaptation usually only takes a week or so. Obviously the entire process, reaching an equilibrium, can take much longer.

 

[Bradders]

Yes, it does your head in a little when you think about it! I have battled this myself many times and sent myself into a loop. So where did I get to?!

I think the answer is that the reproduction of bacteria will slow down. So your mature filter will have tonnes of good stuff in it already, and your new filter will have none and will need to colonise. So the same amount of food means your mature filter reproduction slows down (who cares, there is tonnes of the suckers in there!) and your new filter slowly ramps up.

If you are cycling both filters at the same time with no fish in the aquarium, you can up the food. But I would not increase the food in an established tank with fish as that would cause health issues.

 

[ScareCrow]

I normally take the approach of mixing some media from a well established filter in with new media, in a new setup and replace what I've removed from the established filter with new media because of this:

generation times for nitrifying microorganisms are measure in hours and reproduction is by binary fission and therefore potentially exponential.

I then just limit feeding in both tanks for a couple of weeks until I'm confident things are starting to mature.
To me adding an additional filter to a tank to colonise it with bacteria raises a couple of questions.
How long do you run it to colonise it sufficiently?
Does it have a diverse enough population of bacteria (higher flow rate of a new filter unimpeded by accumulated organic matter etc might favour a narrower diversity of bacteria)?
Also I don't have enough room in my cabinets for additional filters so swapping media saves that storage problem.

 

[dw1305]

Hi all,

To me adding an additional filter to a tank to colonise it with bacteria raises a couple of questions.
How long do you run it to colonise it sufficiently?

There is some discussion in: <"Correspondence with Dr Ryan Newton - School of Freshwater Sciences, University of Wisconsin—Milwaukee"> and

Does it have a diverse enough population of bacteria (higher flow rate of a new filter unimpeded by accumulated organic matter etc might favour a narrower diversity of bacteria)?

<"The nitrifying microbes in aquariums and cycling">.

cheers Darrel

 

[ScareCrow]

Hi all,

There is some discussion in: <"Correspondence with Dr Ryan Newton - School of Freshwater Sciences, University of Wisconsin—Milwaukee"> and

<"The nitrifying microbes in aquariums and cycling">.

cheers Darrel

Thanks Darrel,
The first link, to me reads that taking filter media from a mature source is one approach used in their experiment and is the preferred option. Nitrifiers may come from a number of sources, including tap water. So my interpretation would be that while running a filter on an established aquarium would expose the filter to more nitrifiers than appear in tap water (hopefully at least) but there's still going to be a lag in the bacteria colonising the filter.
The second link and links to me suggest that there probably are specific environmental conditions required by the various species of nitrifiers. So maybe a combined approach is best. Add some media to the new filter and also run it on an established aquarium for a while. Helping speed up colonisation as well as creating the specific environments required by the bacteria as the media will be exposed to the same conditions required to create the desired environments for the various bacterial colonies.

 

[fredi]

O

Thanks Darrel,
The first link, to me reads that taking filter media from a mature source is one approach used in their experiment and is the preferred option. Nitrifiers may come from a number of sources, including tap water. So my interpretation would be that while running a filter on an established aquarium would expose the filter to more nitrifiers than appear in tap water (hopefully at least) but there's still going to be a lag in the bacteria colonising the filter.
The second link and links to me suggest that there probably are specific environmental conditions required by the various species of nitrifiers. So maybe a combined approach is best. Add some media to the new filter and also run it on an established aquarium for a while. Helping speed up colonisation as well as creating the specific environments required by the bacteria as the media will be exposed to the same conditions required to create the desired environments for the various bacterial colonies.

when I set up my new tank
I used trays from filters on mature tanks (same filters), I was using aqua soil which was leaching ammonia (3ppm measured), the tank 700ltrs, took a week to cycle, no measurable ammonia, no measurable nitrite.
It just works
I am not saying there are not other methods which work, and for plant only aquaria, other methods may well work better, but if you want to add fish (at a sensible rate), this is what I would choose to do

 

[Bradders]

Add some media to the new filter and also run it on an established aquarium for a while. Helping speed up colonisation as well as creating the specific environments required by the bacteria as the media will be exposed to the same conditions required to create the desired environments for the various bacterial colonies.

That would make sense to me.

In fact, that is what I have done by adding my second Oase 250 onto the current aquarium during November. (I can tell you, euro braces are a real pain!) I intend to get a secondary aquarium in the next three months and will be using that semi-matured filter on the new tank. You don't need a lot of media for converting Ammonia to Nitrate, so the 3 months + would be more than enough to support the next aquarium initially. And I'll be testing in the new aquarium, just for belt and braces.

 

[dw1305]

Hi all,

The first link, to me reads that taking filter media from a mature source is one approach used in their experiment and is the preferred option

Definitely my preferred option. After that? Probably <"Secret Ingredient Soup">

Nitrifiers may come from a number of sources, including tap water

That is an interesting question. It looks like COMAMMOX Nitrospira and Ammonia Oxidising Archaea (AOA) are pretty much universal in low ammonia situations, but that could be because,

• they are very efficient at finding these resources, or
• it could be because they've had a very long time (most of the last 3.5 billion years) to become universal or
• a combination of both factors.

I don't know the answer to that one, again I'd guess it is a mixture of both factors, but I have no idea of the relative proportions of "found it" to "sat waiting".

That is really the question we <"still don't have answer to">, but remind me in ten years time (when we should have an answer), but I'm going to guess that sources of inoculum are pretty widespread.

The second link and links to me suggest that there probably are specific environmental conditions required by the various species of nitrifiers.

I think so. I'm pretty sure that <"low ammonia loadings"> will, over time, create a much more diverse and resilient microbial flora. I don't know much about microbes, but that is how things <"usually work in Ecology"> - <"The nitrifying microbes in aquariums and cycling">

cheers Darrel

 

[Tim Harrison]

flora. I don't know much about microbes, but that is how things <"usually work in Ecology"> - <"The nitrifying microbes in aquariums and cycling">

Me neither but it sounds right. Nutrient poor habitat is usually the most diverse. Classic example is wildflower meadows. The poorer the soil the greater the species richness and diversity. Higher nutrient load often favours one or two competitive species. It’s why most folks fertilise their lawns, it favours species like perennial ryegrass, over all but the most persistent weeds.