# Can/Should you store the filter mulm??



## niru (8 Feb 2012)

Hi All

I intend to rescape my tank sometime soon, and as a part of that would like to use the filter mulm to aid substrate maturing process. I also need to clean my filters much sooner as a part of routine chores on the existing tank. 

Can I start collecting the mulm in these filters and store them for a future use? Is this a good idea, and whats the best way to do so? Does having a air pump through the muck help keep it alive, or it doesnt matter since its the humic stuff and other acidic/organic junk one is interested in it & not the bacteria per say?

-niru


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## skeletonw00t (8 Feb 2012)

Is mulm good? I thought it was just accumulated dirt? Doesnt the good bacteria grow inside the media?


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## niru (8 Feb 2012)

Yes, but its advised to use it at substrate level below the top gravel/Acadama etc to help kick start the bacterial maturing process... Hence the question is only about using the mulm in a new substrate...

cheers
niru


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## Radik (8 Feb 2012)

Bacteria in mulm will die from lack of food if placed away from filter. Maybe you can feed some ammonia from pound shop.


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## niru (8 Feb 2012)

Radik said:
			
		

> Bacteria in mulm will die from lack of food if placed away from filter. Maybe you can feed some ammonia from pound shop.



Thats what I thought.. ammonia aided by airstone..... But havent read anyone do this .. hence the original question.

I plan to do 2 or more dumpings of the mulm and get a "concentrated" slurry that I can use in the new rescape substrate at the bottom layer, topped by some good soil/gravel/acadama etc..

-niru


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## Radik (8 Feb 2012)

you can try, I think there somebody did calculations on internet how much 1 drop of ammonia translates in to PPM per gallon of water. You feed it and see if ammonia is gone or lower next day, if yes you have active colony.


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## dw1305 (8 Feb 2012)

Hi all,
I think you should be able to store it almost indefinitely in a bucket. I wouldn't feed it with ammonia, but just with the occasional dead leaf etc. 

A couple of times when we've had a bit of time at the end of  a microscopy practical I've squeezed out a filter sponge and the students have  had a go to see what they can in the mulm suspension, they are looking at larger organisms like rotifers, cyanobacteria, protista etc rather than bacteria, but it is quite surprising what you can find.

We used to have a "Winogradsky column" set-up as well (in a glass "spaghetti" jar) <http://www.biology.ed.ac.uk/research/groups/jdeacon/microbes/winograd.htm>, which gives you a range of aerobic/anaerobic environments.

cheers Darrel


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## Greg's Pea (8 Feb 2012)

Also, don't underestimate how long bacteria can survive at sub 5C temps. We used to ship Nitrosomonas & Nitrobacter to water companies after they had been refrigerated for up to a few weeks before loss was notible.


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## niru (9 Feb 2012)

dw1305 said:
			
		

> Hi all,
> I think you should be able to store it almost indefinitely in a bucket. I wouldn't feed it with ammonia, but just with the occasional dead leaf etc.
> 
> A couple of times when we've had a bit of time at the end of  a microscopy practical I've squeezed out a filter sponge and the students have  had a go to see what they can in the mulm suspension, they are looking at larger organisms like rotifers, cyanobacteria, protista etc rather than bacteria, but it is quite surprising what you can find.
> ...



Thats a great read    Darrel! Many thanks..

Do you think air stones are needed, or occasional (daily once) stirring vigorously would suffice? Will keep the bucket in light for sometime.. Also, wont other nasties like fungus, or something alike pest this mulm slurry in the open? 

-niru


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## dw1305 (9 Feb 2012)

Hi all,


> Do you think air stones are needed, or occasional (daily once) stirring vigorously would suffice?


Probably depends a little bit on how much mulm there is. As long as the amount (bioload) is fairly small and the bucket is somewhere coolish (but not cold) I think an occasional stir should be fine. I think ambient light should do as well. 
I should have said I would add some of the existing (or existing plus new) substrate to the bucket with the mulm.  



> Do you think air stones are needed, or occasional (daily once) stirring vigorously would suffice? Will keep the bucket in light for sometime.. Also, wont other nasties like fungus, or something alike pest this mulm slurry in the open?


 I wouldn't worry too much about other things growing, microbial communities are much more diverse than we might imagine and will react fairly quickly to changes in conditions or food source. As long as you have some of the organisms you want when the conditions change to favour them they will grow. 

cheers Darrel


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## mlgt (9 Feb 2012)

Ive stored mulm for a day or two but did not know I could keep mulm for that long a period.
Having no access to branded sands when I first started keeping plants I was told mulm is a good substrate booster and Ive grown many successful tanks the same way.

Thanks for the info Darrel. Interesting science project too


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## Viv (9 Feb 2012)

I never would have thought of using mulm like this so thanks for this thread!

Viv


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## niru (9 Feb 2012)

Hi

thanks Darrel, as always you put things in clear, scientific perspective... 
Another question: How long can this be kept, and since it get "concentrated" with time (water evaporation etc) does it increase its benefits when added under a new substrate?

Viv: Everytime I clean the filters, I throw this muck away though I know the goodies contained in it. Never actually bothered much though. But I plan to do a rescape soon and want to use akadama (thanks to James' marvelous thread on it) boosted by this mulm. Plus my filter needs a much sooner cleaning. Hence the OP. 

-niru


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## Viv (9 Feb 2012)

Filter muck (pond and tanks) usually goes in the composter, so not totally wasted but this sounds like a much better use of it! Itching even more to do another tank now though!!

Viv


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## dw1305 (10 Feb 2012)

Hi all,


> Another question: How long can this be kept, and since it get "concentrated" with time (water evaporation etc) does it increase its benefits when added under a new substrate?


 No, I think what you end up with will depend upon the food supply (organic matter), O2 content of the water and the nature of the substrate. I don't see why it can't be stored almost indefinitely, but I would definitely use it fresh if I could as the fresh mulm should have an appropriate microbial community and this will change with the changing conditions.  My suspicion would be that over time  the "ordinary" bacteria will tend to out-compete the nitrifying _Nitrobacter_ & _Nitrosomonas_ bacteria.

cheers Darrel


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