Filter Media for Fish Stocking Calculator

[Bradders]

Hi All,

I have been developing a simple spreadsheet model which allows you to select your filter media type and the amount of media (inch/3), and it will spit out some values for a) crystal clear stocking levels and b) ammonia-only stocking levels.

This is based on data provided by Dave at Aquarium Science (and scientific data on effective filter media surface area), and I just took his math and created a straightforward spreadsheet. I know some of you have raised concerns with Dave's data on planted aquariums, but I feel his filter sections are very good for obtaining a feel (or at least a consideration) for how to potentially stock your filter. As many of you are acquascapers and planting experts, I understand that the below model will not take into account all the other important factors (plants, substrate, rocks. aeration, flow etc) within the aquarium - nor does it take into account the size of an aquarium and the ethics of fish stocking. But playing around with the figures and different media types is quite interesting.

Does anyone find this interesting? If so, I'll try to brush up my Excel skills a little more and post on here somehow.

BTW - the screenshot below is the output of my Oase Biomaster 250 when I pump the data into the model. (And yes, I did actually measure the cubic inches of media as I am just that sad! )

Regards,
Brad

 

[Bradders]

Well, I brushed up on my Excel skills anyway! It was fun!

If interested, have a play with the below Excel sheet - you should be able to download it from the link below. Interesting to see how easy it is (just taking into account aquarium filters only) to address Ammonia compared to moving the dial on very clear water.

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[hypnogogia]

And yes, I did actually measure the cubic inches of media as I am just that sad!

How?

 

[Bradders]

How?

It's mainly foam with holes cut out to fit the Oase Biomaster, so it was pretty easy thankfully. (W x D x H - Hole).

 

[Le duke]

I did the same calculations a while back. Ended up swapping out the 30ppi foam in one of my FX filters for Poret 20ppi. Still have a LOT of “excess” filtration, aka my FX4 is unnecessary when I have the FX6 as well, but I’m fine with that. I like redundancy.

And, my water clarity. Wow.


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[erwin123]

In the nitrogen cycle, nitrifying bacteria utilize oxygen and alkalinity in the process of converting ammonia and nitrite into nitrate which is less toxic to fish (Francis-Floyd et al., 2020). Malone and Beecher (2000) recommended 2.5–3.0 g O2/m3media/day volumetric oxygen conversion rate in recirculating aquaculture biofilters installed in grow out systems. Between weeks eight and ten of the current study, biofilters containing coconut shells, plastic and horns, demonstrated high and recommended oxygen conversation rate of 3.6 ± 0.1, 3.0 ± 0.1 and 2.8 ± 0.2 g/m3 media/d, respectively (Fig. 3). This implies that, the particular biofilters could provide a denser and more active biofilm compared to the other tested biomedia. From the first to the fifth week, the levels of oxygen conversion in all six tested biofilters were still below the recommended amount and this shows that the nitrifying bacteria community was not fully developed (DeLong and Losordo, 2012). From the sixth to the tenth week, two of the biofilters (biofilter with charcoal and biofilter with ceramic beads) maintained a low volumetric conversion rate. This implies that charcoal and ceramic beads biomedia could not provide sufficient or conducive environment for development of sufficient quantity of bacteria compared to the other media tested

https://www.sciencedirect.com/science/article/pii/S0959652622025227

There has been quite a bit of research done on filter media efficiency for aquaculture. K1's good performance is validated in this survey but what is interesting is coconut shells as a possible sustainable alternative to plastic.

 

[Bradders]

I did the same calculations a while back. Ended up swapping out the 30ppi foam in one of my FX filters for Poret 20ppi. Still have a LOT of “excess” filtration, aka my FX4 is unnecessary when I have the FX6 as well, but I’m fine with that. I like redundancy.

I think the FX4 and FX6 combination is always going to be great! I have heard many great things about Fluval filters but never had the pleasure of running one!

At a raw level, I think the model is a great way to provide an understanding of media quantity versus media efficiency - and that there is a difference between what volume is required for nitrification and clear water columns. Of course, it does not consider the flow rate, oxygen exchange and many other factors. But it stands well as a single lens into one aspect - filter media.

 

[Bradders]

There has been quite a bit of research done on filter media efficiency for aquaculture. K1's good performance is validated in this survey but what is interesting is coconut shells as a possible sustainable alternative to plastic.

It looks like a great article, which focuses on nitrification. I have had a brief read but will read it in detail over the weekend. But great to look into sustainable alternatives.

 

[hypnogogia]

Ended up swapping out the 30ppi foam in one of my FX filters for Poret 20ppi

Even though, according to the table, 30ppi foam is more efficient that 20ppi form?

 

[Bradders]

Even though, according to the table, 30ppi foam is more efficient that 20ppi form?

I would suspect that @Le duke has so much filtration that moving down from 30PPI to 20PPI did not matter, and in the process, it means that the coarser foam (20PPI) blocks less and leads to longer cleaning times. i.e. trying not to clean Biomedia until you really have to. I have so far gone 7 months without having to clean the Biomedia, only the pre-filter is cleaned + standard water changes and tidies.

 

[dw1305]

Hi all,

This is based on data provided by Dave at Aquarium Science (and scientific data on effective filter media surface area), and I just took his math and created a straightforward spreadsheet. I know some of you have raised concerns with Dave's data on planted aquariums, but I feel his filter sections are very good for obtaining a feel (or at least a consideration) for how to potentially stock your filter.

I also think the <"Aquarium Science"> pages are good on filter media <"7.2.11. Ceramic Media in Aquarium Filters"> and nitrification <"6.2. Biofiltration in an Aquarium">, mainly because he has <"insane stocking levels"> and no plants, so he needs to process a lot of ammonia without the addition of the <"extra oxygen from photosynthesis">. There are some thoughts on this here: <"Bio Media for Planted Tanks.">

. Ended up swapping out the 30ppi foam in one of my FX filters for Poret 20ppi. Still have a LOT of “excess” filtration, aka my FX4 is unnecessary when I have the FX6 as well, but I’m fine with that. I like redundancy.

I would suspect that @Le duke has so much filtration that moving down from 30PPI to 20PPI did not matter, and in the process, it means that the coarser foam (20PPI) blocks less and leads to longer cleaning times. i.e. trying not to clean Biomedia until you really have to. I have so far gone 7 months without having to clean the Biomedia, only the pre-filter is cleaned + standard water changes and tidies.

and I think this is getting to the heart of the matter, it <"isn't the media"> that matters, <"it is the level of dissolved oxygen"> in the filter.

There has been quite a bit of research done on filter media efficiency for aquaculture. K1's good performance is validated in this survey but what is interesting is coconut shells as a possible sustainable alternative to plastic.

I'm a <"floating cell media fan"> & <"Is expensive bio media worth it?">. We have a thread <"Is expensive bio media worth it?">.

I also have concerns about plastic media, and I am going to replace my K1 type media, when it / if it starts to disintegrate, <"with a recycled alternative">.

cheers Darrel

 

[Bradders]

I also think the <"Aquarium Science"> pages are good on filter media <"7.2.11. Ceramic Media in Aquarium Filters"> and nitrification <"6.2. Biofiltration in an Aquarium">, mainly because he has <"insane stocking levels"> and no plants, so he needs to process a lot of ammonia without the addition of the <"extra oxygen from photosynthesis">. There are some thoughts on this here: <"Bio Media for Planted Tanks.">

Aquarium science has been one of the great reading sources since I restarted my aquarium. Dave's ethos (in terms of filtration) seems to be two things:

1. Nitrification is (of course!) very important, but not the only factor a filter should provide.
2. Very clear and (relatively) bacteria-free water columns are harder to achieve and require the right media in the right quantity per fish volume.

I have used his website/data to create my filtration - especially when you consider that I was more a fish person than a plant person until I found this forum! I went a bit mad on Friday and did a basic experiment to see if I could be very disruptive with my aquarium to see if it could 'take it'. It seemed to do very well, which I feel points to the bio media within the Oase (alongside some good aeration and flow).

 

[fredi]

Hi all,

I also think the <"Aquarium Science"> pages are good on filter media <"7.2.11. Ceramic Media in Aquarium Filters"> and nitrification <"6.2. Biofiltration in an Aquarium">, mainly because he has <"insane stocking levels"> and no plants, so he needs to process a lot of ammonia without the addition of the <"extra oxygen from photosynthesis">. There are some thoughts on this here: <"Bio Media for Planted Tanks.">


and I think this is getting to the heart of the matter, it <"isn't the media"> that matters, <"it is the level of dissolved oxygen"> in the filter.

I'm a <"floating cell media fan"> & <"Is expensive bio media worth it?">. We have a thread <"Is expensive bio media worth it?">.

Flow through the media is most important imho
As soon as flow is reduced, areas of low/no flow will be present
Not only reducing effective area, but also reducing oxygenation

 

[Bradders]

Flow through the media is most important imho
As soon as flow is reduced, areas of low/no flow will be present
Not only reducing effective area, but also reducing oxygenation

Agreed, you need flow through the filter. (Although there is a debate that the difference between, for example, 3x and 10x is pretty negligible - you need enough for bacteria to live).

 

[Le duke]

I would suspect that @Le duke has so much filtration that moving down from 30PPI to 20PPI did not matter, and in the process, it means that the coarser foam (20PPI) blocks less and leads to longer cleaning times. i.e. trying not to clean Biomedia until you really have to. I have so far gone 7 months without having to clean the Biomedia, only the pre-filter is cleaned + standard water changes and tidies.

Correct.

I didn’t need more biofiltration volume (or, surface area per unit volume, to be more accurate), I needed more throughput. And the central chamber on an FX2/4/5/6 comes with a stock 30ppi foam pad(s) which get gummed up after a while, but don’t provide all that much more carrying capacity, in the grand scheme. It’s a single ~6” diameter, 1” thick 30ppi disc that acts almost like a valve on the entire filter.


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[dw1305]

Hi all,

Flow through the media is most important imho
As soon as flow is reduced, areas of low/no flow will be present
Not only reducing effective area, but also reducing oxygenation

That was where it started for me. There seemed to be a total disconnect between the size of people's filters and their nitrification potential.

I knew that people had many, many times the physical volume of filter media they required, so it had to be something else.

Cheers Darrel

 

[dw1305]

Hi all,

Agreed, you need flow through the filter. (Although there is a debate that the difference between, for example, 3x and 10x is pretty negligible - you need enough for bacteria to live).

It really depends on the bioload, you just need the amount of dissolved oxygen to always exceed the Biochemical Oxygen Demand (BOD) of the tank water.

<"Nothing else really matters">. All the issues come if the water <"becomes deoxygenated in the filter">.

Wet and dry trickle filters have slow flow, but enormous nitrification potential, because of their huge gas exchange surface area.

Cheers Darrel

 

[Bradders]

I have updated a little - mainly because I cannot stop tinkering!

• Added some examples of Oase and Seachem Tidal filter calculations.
• Added 500Ft/2 of surface area calculation, to complement 100Ft/2 and 7Ft/2.
• Added some calculations on fish food feeding for 0.5%, 1% and 2% of weight.
• Added some calculations for minimum aeration per the calculated maximum fish stocking the filter can accommodate.
• Added some notes to ensure people understand these are indications and don't include other factors like plants.

Link below if you want to try - just for fun.

iCloud Drive - Apple iCloud

 

[Le duke]

I did this for my FX6 and FX4 a while back.

I’ll add the numbers to your doc when I get a chance.

I know that Fluval’s big filters aren’t hugely popular in the UK but an FX4 or FX6 with its output split two ways would be a life changing experience for some of you guys. Even on a 90cm tank.

As an example, my FX6 has 737 cubic inches of foam media. Almost twice an Oase 850.


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[hypnogogia]

I have updated a little - mainly because I cannot stop tinkering!

• Added some examples of Oase and Seachem Tidal filter calculations.
• Added 500Ft/2 of surface area calculation, to complement 100Ft/2 and 7Ft/2.
• Added some calculations on fish food feeding for 0.5%, 1% and 2% of weight.
• Added some calculations for minimum aeration per the calculated maximum fish stocking the filter can accommodate.
• Added some notes to ensure people understand these are indications and don't include other factors like plants.

Link below if you want to try - just for fun.

iCloud Drive - Apple iCloud

Do you think there’s any merit in converting to metric?