How Important Is Bio Media?

[tcarswell]

Ive been saying the same thing for quite some time. All the filter companies seem to really like selling bio media that is simply overkill. And to add insult to injury they tell the novice aquarium guys bio media needs to be changed out on a regular basis. The stuff is expensive!

 

[snarferer]

It is quite funny how terribly we kept fish just 10 years ago.
How did they even survive?





I think people with little common sense given a little bit of knowledge tend to freak out and become judgmental.
I had three oscars 10 years ago grow to full size AND breed in a 125gal with only a UGF. Yet you read on the forums now that people want a single oscar in a 125. ANYTHING ELSE IS cruel!!!!!!!!!!

Sorry for the thread derail, but I'm surprised flame war 2009 hasn't started about you dare suggesting anything against the gospel of bioballs!

 

[spiff]

To be fair, you should also say that "not all media can adequately function as bio-media" though too.

UGF, large foam filters, ect all work great as bio-media too. But cartridge filters don't. I bet sand canisters don't either as they tend to get packed down.

 

[Toby_H]

I can remember having a 20g tank that had 6 fancy guppies in it set up for months and i went and bought 4 cardinal tetra's and caused a ammonia spike and a week long mini cycle.

And i certainly don't get that type of thing nowadays with my new age filters and media's.

I’m by no means arguing that the experience you stated isn’t true… although it seems odd…

We are dealing with the same species of bacteria today as we did back then… and as long as there is enough surface area for it to flourish on it should expand at the same rates… and since in your system 15-20 years ago it eventually expanded it seems there was enough surface area to support the larger bacterial colony…

As long as you had ample flow rates in the tank I don’t see why it wouldn’t have absorbed the “mini cycle” just as well as our tanks today do…

a ugf provides plenty of biological space for bacteria to grow. its actually the strong point.

Actually if you do the math to determine the actual surface area of typical gravel depths in a tank and compare that the surface area in a sponge (AC 110 block sponge for example) you’ll find UGFs are working with far less surface area than most people suggest…

But you are right, the lower amount of surface area is still enough to make them suitable ‘Bio Filters’. Which fully supports my theory that we need far less “surface area” than manufacturers have lead us to believe.

i agree it useless after a certain point but the use of increased surface media allows a heavier fish load then the tank could normally support.

One of the main points I stress when mentioning my perspective on Bio Media is that once we have “enough” everything more has no benefit. Having more than enough to a degree is wise (IMO), as this gives you ‘room for growth’ or a buffer zone… but having 7,000 times more than enough 6,998.5 times in the excessive category…

btw i hope your still doing the surface area experiment. because truthfully i will be impressed if you could stock the tank to halfway what i consider a normal bioload with filters.

I still am and I will share details as validated information is discovered.

At this point the bare 10 gal is converting 5 ppm of ammonia added daily without a hitch. Adding more than this becomes a touch more difficult as it requires me to add ammonia twice per day since going beyond 5 ppm has been reported to be toxic to the bacteria itself…

I’m also lagging to allow a bare 20 gal with sponge filter to catch up to the 5 ppm per day rate… I started it several days later…

Not different but people say that the bacteria are stronger because of the higher oxygen content in the trickle flow of a wet and dry filter.

Just another myth.

Trickling and or air stones, venturi's, etc, etc do not add oxygen.

They aid in allowing the co2 to gas out of the aquarium water. thats it. So if you have enough agitation to properly gas out the built up co2 then submerged media is just as strong.

Water has an equilibrium point of oxygenation it will strive to be at… this level will change based on temperature, elevation (atmospheric pressure) and salinity (other factors may apply but are minimal compared to these three).

A Wet/Dry design will aid the water to be at this equilibrium when the water moves over the media… Also, as Dwilder mentioned, the bacteria can get oxygen from the air itself…

I have read at a point of “oxygen saturation” the bacteria can/will thrive, therefore grow faster, therefore split sooner (note: bacteria does not “reproduce” it grows, then splits into two… likewise bacteria does not get old and die provided conditions support it).

I’m not saying your wrong HybridTheoryD… just adding related principals to your valid point…

bio media is very important just what kind and how much surface area needed is greatly exagerated simple sponge filters work great some of the high surface medias are only necasary imo when space is very limited

While I agree with your post in principal… I would like to add that I believe some medias with extremely high “surface area” per volume supply that “surface area” in such confined spaces, water can not readily access it and therefore bypasses it making it a waste of space… when space is limited…

Bio media is definitely important - it's just that in the old days it was in sponge filters and the substrate (UGF).

Canisters have replaced that because they can hold a bigger amount (thus allowing more / larger fish with a larger waste output) and they can be cleaned easier then UGF plates.

Again while I agree with the general viewpoint… I feel there is an exaggeration here.

In my experience, a typically decorated aquarium with a suitable amount of simple Aqua Clear HOB filtration will have ample “surface area” to accommodate a full stock load. In my experience, without using any bio media, aggression limits my stocking well before ammonia to nitrate bio filtration… When dealing with less aggressive Cichlids I find that nitrate build up limits my stocking prior to ammonia to nitrate bio filtration… I don’t keep enough non Cichlid to have an opinion on that angle…

Thus, based on my experience, the amount of surface area needed to house an adequate amount of bacteria is grossly exaggerated in the mind of the typical hobbyist I see posting in such forums…

Ive been saying the same thing for quite some time. All the filter companies seem to really like selling bio media that is simply overkill. And to add insult to injury they tell the novice aquarium guys bio media needs to be changed out on a regular basis. The stuff is expensive!

LOL, Never take advice from the guy who makes a profit off of you taking his advice…

I'm surprised flame war 2009 hasn't started about you dare suggesting anything against the gospel of bioballs!

I played my cards right and worded things carefully in my first post… and I confess I got darn lucky that the first group of posters to reply did so in a very mature manner sharing their experience…

I hope I wrote this reply well enough to encourage the maturity to continue… we’ll see…

To be fair, you should also say that "not all media can adequately function as bio-media" though too.

UGF, large foam filters, ect all work great as bio-media too. But cartridge filters don't. I bet sand canisters don't either as they tend to get packed down.

That is a valid perspective that I lover looked. I started using Aqua Clear filters as my sole HOB filter quite a few years ago for a lot of reasons…

I wouldn’t be willing to speculate on a judgment of sand filters either way though… They are “packed” loose enough for water to flow through them, but I don’t know if that is enough space for bacteria to develop in…


Thanks to everyone who took the time to read my long winded post (and if you didn’t you should have )

And thanks even more to all of you for keeping the responses mature!

 

[Noto]

Not different but people say that the bacteria are stronger because of the higher oxygen content in the trickle flow of a wet and dry filter.

Just another myth.

Trickling and or air stones, venturi's, etc, etc do not add oxygen.

They aid in allowing the co2 to gas out of the aquarium water. thats it. So if you have enough agitation to properly gas out the built up co2 then submerged media is just as strong.

This is not true. Ordinary atmospheric air has much higher concentrations of both CO2 and O2 than water can hold, even at saturation. These gases will tend to diffuse down the concentration gradient, into the water. Agitation, trickling, etc. increase the rate of diffusion by increasing the water/air contact area and by breaking up the gas-rich surface layer which tends to form in still water. So these methods increase the amount of oxygen and CO2 in the water.

More importantly, and as nc_nutcase already mentioned, the bacteria in a trickle filter can carry on gas exchange directly with the atmosphere (so long as they stay wet). So they have access to far more O2 than submerged bacteria do and so can metabolize ammonia and nitrites more quickly.

NC_nutcase, I see your point but I think your wording is a little misleading. Bio media is crucial, but bio media covers a broader range of materials than the suppliers would have you believe.

 

[brianp]

I have ample experience with freshwater Cichlid aquariums being able to maintain 0 ammonia and 0 nitrite with no special “bio media”… Therefore I often suggest it’s importance is grossly exaggerated…

‘Back in the day’ we didn’t have canisters and we didn’t use bio media. So be it we did a whole lot ‘wrong’ according to today’s knowledge & standards (at least many of us did)… but once a tank was mature, keeping zero ammonia and nitrites was simple with UGFs, sponge filters and HOBs.

I commonly hear it stated that sponge filters are great little bio filters… and then I hear the same people saying that an Aqua Clear HOB is not a good bio filter because it only has a sponge for media… read that one again…

A typical HOB filter creates a lot of ‘surface agitation’ where the intake tube enters the HOB. The freshly oxygenated water is then pulled down into the HOB and through it’s media. The water that runs through “bio media” within a canister filter has not been freshly oxygenated such as this has…

The more “surface area” per volume “bio media” has, the smaller the pores in the material are. Since water has this tendency to follow the path of least resistance, I would like to suggest that the vast majority of the water moving “through” your bio media simply skims over the surface of the nuggets. This very simple principal is vastly overlooked as bypass.

I have run several 75 gal tanks with two AC 110s with no media expect a stock sponge typically stocked tanks for years on end without ever experiencing an ammonia or nitrite spike.

I am currently running a 125 gal filtered by two AC 110s with nothing more than stock sponges and two Mag 250s with micron cartridges. This tank has 2 adult Blue Dempseys, 25~35 2.5“~5” Geos, a few small Dempsey grow outs and a 12” BGK. The tank consistently has zero ammonia and zero nitrite.

Unfortunately I had to move out of the home where I had my fishroom, but up until this past winter I had a fish room which contained 5 tiers of two 50 gals stacked over a 75 gal each plumbed together as a 175 gal system. Each bottom 75 gal was filtered by one AC 110 and there was either a 500 or 700 gph pump moving water from the bottom (75 gal) to the top (50 gal) with nothing but a small sponge prefilter.

These tiers were either moderately stocked with adults or pairs or heavily stocked with grow outs. Heavy water changes were done frequently as nitrates built up fast, yet I never had any ammonia or nitrite spikes.

For the last 7 years I’ve maintained between 300 ~ 1,500 gallons of aquariums and have been reading ample material both from the aquarium hobby and beyond to better understand my aquatic systems (As I get older the fishroom has become more fun than the bar)… In my experience a mature system will not lack sufficient “surface area” to maintain an adequate bacterial colony to accommodate it’s fish load…

An exception to that theory may be a bare tank that is overstocked. I have never kept fish this way and therefore cannot speak about it’s needs from experience.

I would like to acknowledge a benefit to a wet dry filter. This not only offers increased “surface area” but offers it at a point of oxygen saturation. From the information I’ve read it is true that in this environment our bacterial colonies can/will be more healthy, grow faster and split/reproduce more readily.

The benefit I see Wet/Dry filters offering is that if for some reason the ammonia production in the tank increases, the bacterial colony can increase along with it at a faster rate. Although in reality how beneficial this is questionable, in typical conditions the bacteria we house has a “doubling rate” of 4~6 hours. Therefore it can grow quite quickly even without these special conditions.

I do not expect me sharing my understanding is going to make any revolutionary changes in the way people in general filter their tanks… But I do hope it helps a few people think their filtration through from a slightly different perspective. I feel that the filter/media manufacturers have fuels a vast misunderstanding in “bio needs” and are making a fortune from it.

Well, each of us has our own “take” on various technical issues. I wanted to offer a few comments in response to your remarks to flesh this out a bit more.

First, it's true that in the "early days", we didn't employ "biomedia", per se. However, we did use a lot of activated carbon, polyester filter floss, sponges and undergravel filters...all of which had a great deal of surface area for bacterial colonization. So, regardless of whether you refer to it specifically as biomedia, its effect is the same.

When we refer to the "surface-to-volume ratio", we are generally referring to the SIZE of a particle...and smaller particles have a higher ratio than larger particles. For example, a golf ball has a smaller sv ratio than a marble. So if we had a liter of golf balls, it would have less total surface area than a liter of marbles.....provided that they were made out of the same material. Starting with the sv ratio, the surface area of a particle can be further increased by adding "texture" to the particle. Texture is created by pores (as you stated), furrows, dimples, etc.

A network of small pores has a greater surface than one large pore occupying the same space and that is precisely why gas exchange occurs through capillary beds, rather than arteries. In a biofilter bed, you actually want the water to skim over the particles and the best particle types do not have a fine system of pores because, as you point out, the moving water doesn’t make contact with the particle interior through these pores and diffusion is not efficient enough to move oxygen, ammonia, nitrite, etc., into a particle’s interior through a network of fine, lengthy pores. However, if a particle with the right sv ratio and one which does not pack too tightly has a surface populated with shallow pores or furrows, then the surface area of that particle can be increased dramatically and all of this surface area IS accessible to the diffusive movement of various constituents as the water moves over these particles. The transfer of oxygen to the bacteria, the transfer of ammonia to the bacteria, the removal of nitrite and nitrate from the bacteria, etc., is NOT a direct function of water movement over the particles’ surface, but rather, is the direct result of the two-way diffusion that is occurring within the water as it is moving over the particles. When water moves over a particle surface, this is not “bypass”. Bypass is when the water is diverted around the biofilter particle bed or diverted around the mechanical filter bed, for that matter.

The benefit of a wet-dry is NOT that it offers increased surface area...it does not. We know this because wet-dry bioballs have a much larger particle size than typical biofilter particles. Hence, they have a reduce sv ratio. Bioballs are also very smooth and in fact, have very limited total surface area compared to sintered quartz or ceramic biofiltration particles. The only significant benefit (as you stated) is that the atmosphere has a much higher oxygen concentration than water and the aerobic bacteria which oxidize ammonia and nitrite operate at higher metabolic levels when exposed to higher levels of oxygen.

IMO, the use of particles with optimized shapes, sizes (sv ratios), packing characteristics and textures represents a true advancement in the aquarium hobby which allows for more substantially more efficient filtration and improved water chemistry. I do not feel that this is a gimmick on the part of various companies. Biofilters should be viewed as small "reactors" which process various components being generated by the biological activities within the tank. Optimized particles are required for the efficient operation of these reactors.

 

[Toby_H]

NC_nutcase, I see your point but I think your wording is a little misleading. Bio media is crucial, but bio media covers a broader range of materials than the suppliers would have you believe.

On the contrary I think I was rather straight forward with my explanation and do not think you should suggest I’m being misleading… I repeatedly talked about the importance of bacteria as well as traditionally labeled “Mechanical Media” serving as adequate surface area for bacteria…

Well, each of us has our own “take” on various technical issues. I wanted to offer a few comments in response to your remarks to flesh this out a bit more.

Thanks for Chiming in Brian, You always add a well thought perspective.

First, it's true that in the "early days", we didn't employ "biomedia", per se. However, we did use a lot of activated carbon, polyester filter floss, sponges and undergravel filters...all of which had a great deal of surface area for bacterial colonization. So, regardless of whether you refer to it specifically as biomedia, its effect is the same.

My point has been these other forms of filtration exceed the systems need for available surface area… thus rendering fancy “bio media” a wasted investment…

When we refer to the "surface-to-volume ratio", we are generally referring to the SIZE of a particle...and smaller particles have a higher ratio than larger particles. For example, a golf ball has a smaller sv ratio than a marble. So if we had a liter of golf balls, it would have less total surface area than a liter of marbles.....provided that they were made out of the same material. Starting with the sv ratio, the surface area of a particle can be further increased by adding "texture" to the particle. Texture is created by pores (as you stated), furrows, dimples, etc.


A network of small pores has a greater surface than one large pore occupying the same space and that is precisely why gas exchange occurs through capillary beds, rather than arteries. In a biofilter bed, you actually want the water to skim over the particles and the best particle types do not have a fine system of pores because, as you point out, the moving water doesn’t make contact with the particle interior through these pores and diffusion is not efficient enough to move oxygen, ammonia, nitrite, etc., into a particle’s interior through a network of fine, lengthy pores. However, if a particle with the right sv ratio and one which does not pack too tightly has a surface populated with shallow pores or furrows, then the surface area of that particle can be increased dramatically and all of this surface area IS accessible to the diffusive movement of various constituents as the water moves over these particles. The transfer of oxygen to the bacteria, the transfer of ammonia to the bacteria, the removal of nitrite and nitrate from the bacteria, etc., is NOT a direct function of water movement over the particles’ surface, but rather, is the direct result of the two-way diffusion that is occurring within the water as it is moving over the particles. When water moves over a particle surface, this is not “bypass”. Bypass is when the water is diverted around the biofilter particle bed or diverted around the mechanical filter bed, for that matter.

I agree with your explanation here… But the manufacturers of “Bio Media” count the internal pores as surface area thus misleading us as to how much useable surface area they are really giving us… Because the water Bypasses the vast majority of the (internal) surfaces they suggested the media contains.

In reality I would suggest a liter of Bio Rings offer no more usable surface area than a liter sized Aqua Clear sponge…

The benefit of a wet-dry is NOT that it offers increased surface area...it does not. We know this because wet-dry bioballs have a much larger particle size than typical biofilter particles. Hence, they have a reduce sv ratio. Bioballs are also very smooth and in fact, have very limited total surface area compared to sintered quartz or ceramic biofiltration particles. The only significant benefit (as you stated) is that the atmosphere has a much higher oxygen concentration than water and the aerobic bacteria which oxidize ammonia and nitrite operate at higher metabolic levels when exposed to higher levels of oxygen.

Doesn’t the use of smooth walled bio balls with lower available surface area mean those who use them understand that more surface area isn’t what we really need here? ...As that is an essential part of the core of my argument...

IMO, the use of particles with optimized shapes, sizes (sv ratios), packing characteristics and textures represents a true advancement in the aquarium hobby which allows for more substantially more efficient filtration and improved water chemistry. I do not feel that this is a gimmick on the part of various companies. Biofilters should be viewed as small "reactors" which process various components being generated by the biological activities within the tank. Optimized particles are required for the efficient operation of these reactors.

I feel the media manufacturers have convinced most hobbyists that they need far more square units of surface area to house bacteria than is truly needed… I’ve described several set ups that I’ve kept long term that have functioned very well banking on that notion… with no signs of ammonia or nitrite to show…

While I agree we can increase overall surface area with just the right balance of size & shaped media… I don’t see exceeding what is needed by dozens if not hundreds of times what is going to be used, as beneficial…



If a 75 Gal with one AC 110 can keep the ammonia/nitrites of a given stock list at zero… then adding a canister stocked full of bio media is reducing a canister filter into nothing more functional than an overpriced powerhead… and I see this very set up suggested on this and other forums nearly every day…

 

[spaulding]

well, even though you guys make me feel like an idiot, this is a very interesting read. i've never even really considered how that once you have balanced your bio load to bio media, how added media is rather pointless (as in your canister filter/powerhead comment). i think a lot of peoples thinking (myself included) is to overdue it and hope for the best.

 

[dwilder]

the main thing is do what works for you i prefer a media that is cheap has decent surface area is easily cleaned or somewhat self cleaning by this i mean the extra bio sludge that builds up on some of the expensive media rendering them useless.only using sponges in an aquaclear works great i used to use ug filters they worked great just hard to keep clean, a plain sponge filter works good also i will say since i started using bio wheels i fell in love they are the best imo for the size and self cleaning over all i just hate when someone says tons of media is necessary test your water and figure it out

 

[FSM]

You make a good point nutcase. Excess biomedia is pointless, and I have seen zero data which shows how much of the surface area of biomedia is actually used, or how much is actually necessary.



My 29 gallon tank is filtered only by an AC50 with two sponges and some filter floss in it; I'm pretty sure aquaclears didn't even include the dedicated biomedia until fairly recently.

But my 75 has an AC110 and several gallons of bioballs in a sump.

I'm almost completely confident that the sump alone is more than adequate.