Biomedia Prep

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Wells

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I've currently put a couple extra bags of bio media into my filter system with the impression that when I get round to upgrading to a bigger tank in a couple months I will be able to speed up my cycle.

By the time they'll be in there, the media will have run for about 3+ months, am I right in thinking this will have the desired effect?

Is there such a thing as too much media?
 
By the time they'll be in there, the media will have run for about 3+ months, am I right in thinking this will have the desired effect?
Well I suppose that depends on the desired effects :rofl: .

By putting in the extra biomedia you are increasing the available surface area that the nitrifying bacteria are able to colonise. As long as it had a good amount of flow over it and doesn't clog with waste it should provide that.

However, bacteria like everything else can only survive if there is enough stuff to live off. So in theory that media is able to look after that amount of fish, when you transfer it to another tank it still is looking after the same amount of fish. When you go to add more fish, the numbers of bacteria are able to increase as there is more waste to live on. that's why it is good practice not to add too many fish at once.

That being said, when changing tanks you are losing all the bacteria which have colonised the bits of the tank which are not coming into the new tank eg glass so in theory it can provide that important buffer space

Is there such a thing as too much media?

I mean its complicated, how much surface area hold enough bacteria to support the waste conversion of 1 fish?

Take part of this abstract about the mechanics of nitrate production in RAS systems;

"Expressed as volumetric total ammonia-N (TAN) removal rate, the MB filters had significantly higher removal rate (231 ± 17 g N−1 m−3 d−1) compared to the FB filters (92 ± 2 g N−1 m−3 d−1). Expressed as surface specific TAN removal rate MB filters had significantly lower removal (0.27 ± 0.02 g m−2 d−1) than FB filters (0.46 ± 0.01 g m−2 d−1). When conditioned to a higher inlet TAN concentration (6.27 ± 0.39 mg l−1) for 2 weeks, the FB filters increased the removal rate (146 ± 3 g m−3 d−1 or 0.73 ± 0.01 g m−2 d−1) while the MB filters had unaltered performance. The results indicate, that the more heterogeneous and stratified biofilm to be expected in FB, can react more flexibly when challenged with changes such as differences in TAN loading. The effect of dissolved oxygen level on FB filter nitrification rates was additionally tested at TAN 5.35 ± 0.06 mg l−1. Below approximately 60% saturation (7.1 mg O2 l−1) measured at the filter outlet, nitrification rates started decreasing rapidly. "
Suhr, K. I., & Pedersen, P. B. (2010). Nitrification in moving bed and fixed bed biofilters treating effluent water from a large commercial outdoor rainbow trout RAS. Aquacultural engineering, 42(1), 31-37.

This will then obviously change between temperatures, feeding regime, loadings, DO, plants/algae, type of biomedia, age of biomedia ect.
 
Take part of this abstract about the mechanics of nitrate production in RAS systems;

"Expressed as volumetric total ammonia-N (TAN) removal rate, the MB filters had significantly higher removal rate (231 ± 17 g N−1 m−3 d−1) compared to the FB filters (92 ± 2 g N−1 m−3 d−1). Expressed as surface specific TAN removal rate MB filters had significantly lower removal (0.27 ± 0.02 g m−2 d−1) than FB filters (0.46 ± 0.01 g m−2 d−1). When conditioned to a higher inlet TAN concentration (6.27 ± 0.39 mg l−1) for 2 weeks, the FB filters increased the removal rate (146 ± 3 g m−3 d−1 or 0.73 ± 0.01 g m−2 d−1) while the MB filters had unaltered performance. The results indicate, that the more heterogeneous and stratified biofilm to be expected in FB, can react more flexibly when challenged with changes such as differences in TAN loading. The effect of dissolved oxygen level on FB filter nitrification rates was additionally tested at TAN 5.35 ± 0.06 mg l−1. Below approximately 60% saturation (7.1 mg O2 l−1) measured at the filter outlet, nitrification rates started decreasing rapidly. "
Suhr, K. I., & Pedersen, P. B. (2010). Nitrification in moving bed and fixed bed biofilters treating effluent water from a large commercial outdoor rainbow trout RAS. Aquacultural engineering, 42(1), 31-37.

:huh:

Is that in English?

*whhhooooooooossssshhhhhh*
went waaaay over my head!

:blink:
 
:huh:

Is that in English?

*whhhooooooooossssshhhhhh*
went waaaay over my head!

:blink:
Exactly, I have a friend who works in biofilter biology and mechanics during the transition from freshwater to salt water in Atlantic Salmon and I understand nothing of what she says :rofl:

I wanted to use it as an example that the biomedia and nitrifying bacteria is a complicate subject based on many different factors.
 
Thanks for such a detailed response, even if it did take me a couple reads to wrap my head around haha!

The idea is that all the current fish would be transferred and then more added over a staggered period of time so hopefully wouldn't lose any bacteria or overload the current.
 
Yeah, So moving across the media and fish then waiting will allow the bacteria on on the new media to expand and form in the new tank. The extra media can help with this.

Then after a while the media can also help with excess surface area with the new additions.

But will al biological processes it takes a little bit of time
 
When you upgrade a tank (as opposed to keeping both tanks running) the easy option is just to move your entire filter over with the fish.
 
When you upgrade a tank (as opposed to keeping both tanks running) the easy option is just to move your entire filter over with the fish.

So I think that's what he is doing, and just wanting to add extra media into the filter to buffer the loss of cycled surface area on things not being moved between tanks eg glass.
 
Putting extra media in the current tank won't grow any extra bacteria. If the fish bioload stays the same, the number of bacteria stays the same. All that will happen in 3 months is that the bacteria will spread out so there will be some in the new media - but less in the original media.
 
I don't disagree with you I said as much in my first post.

You have the same amount of bacteria in a larger area, as the waste production supporting that population is the same.

However where I think it might be beneficial is having media which is already biologically active rather than adding any excess you might need at the point of transfer or change of tank. a healthy active biofilm is more beneficial than a sterile dry media block, and can react faster to changes in the aquarium.

I don't think, if this was going to be added anyway that there are downsides to this, so much is tank by tank variable that I don' think much can be said with certainty
 
Cheers for the responses.

To make it clear as to what my objective is, I will be running both tanks, my idea was that I keep the original bag of biomedia that originally came with the tank in the existing tank, and put the two extra bags into the new tank to try and cut down the cycle time.

Your responses have cleared it up for me, there's only so much bacteria that can be built up due to the waste load, I've essentially just split it across different loads right?

I didn't know much at all before this forum, it still baffles me that fish shops just tell people to chuck in some starter liquid then get your fish in.
 
I will be running both tanks,
Ah, I was under the impression that you were moving all the fish over and not using the original tank. If you are keeping both tanks running, that's different.

Yes after a couple of months with extra media, the number of bacteria will be the same, just spread out between the old and new media. When you remove the new media it will kick start the cycle in the new tank. The old tank will lose some bacteria but it should make up that loss quickly - keep an eye on the ammonia and nitrite levels to be on the safe side.
 

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