Bacteria on a dirty sponge filter?

[BF McUmber]

With the CO-OP sponge filter being such a coarse sponge, What would happen if you never cleaned it? Would it just slowly catch mulm until it eventually clogged? If so, while the sponge material gets dirty would that dirt buildup inhibit the Beneficial Bacteria's function? 

The context for the question is that I got a random Nitrite spike in my Lipstick goby tank that confuses me and has me thinking about random stuff. The only big change I made to the tank was that I added a heater to bring the tank from 65 to 68 degrees. I hadn't cleaned the sponge in maybe 3 weeks but had gravel vac'ed weekly. With only 3 fish in the tank when I do clean the sponge not much stuff comes out. 

 

[modified lung]

I've cleaned mine once or twice in 2+ years. Every few weeks for the past couple months it clogs to the point it cuts off the air. Good times.

[nabokovfan87]

On 3/29/2022 at 8:52 PM, BF McUmber said:

What would happen if you never cleaned it? Would it just slowly catch mulm until it eventually clogged? If so, while the sponge material gets dirty would that dirt buildup inhibit the Beneficial Bacteria's function? 

Even with the sponge being course, I would still suggest you clean it at least once a week or bi-weekly. I would suggest trying to get the mulm on the substrate and not the filter itself.  Shrimp will graze on the filter and some species also prefer to root around on surfaces embedded with mulm, but with that being said I think that any rocks or other surfaces in the tank, wood, or slow areas of the tank would be a place where you would be able to let that mulm build up.  I used some of the morimo moss balls to create a calm area where the fry would hand in and out.

As to your other question....

Yes, the sponge will clog over time and you will lose filtration. It should not cause a nitrate spoke (that is likely from food).  The sponge is a very "poor" surface for bacteria but it does work.  You're going to have more bacteria on the rocks, sides, substrate, and surfaces of the tank.  If you're really concerned you can add a pile of lava stone, or media in a bag near the sponge and that can also help the tank to "seed" more bacteria.

High flow = more success holding the strong bacteria. Reduced flow means that the bacteria might not be as strong.  Example being something like the..... anoxic type filtration compared to the bubble bio filter available on the co-op.

On 3/29/2022 at 9:26 PM, modified lung said:

I've cleaned mine once or twice in 2+ years. Every few weeks for the past couple months it clogs to the point it cuts off the air. Good times.

 

 

[nabokovfan87]

here is a good conversation on the topic.
 

In my experience with the co-op sponges, I've had the ziss "never clog" airstones clog because they had too much mulm on the felt.  I have also had the sponges themselves fill up with mulm and detritus slightly quicker than I thought because of the flow they were running on was probably higher than others would run them.  I took the stones apart and loosened them a bit. cleaned them, but I would recommend treating the airstones themselves like an impeller on a HoB filter. Every week or bi-weekly clean the sponges, then once a month check and clean out the stone itself.

Edited March 30, 2022 by nabokovfan87

[Odd Duck]

@nabokovfan87, I think you may be mistaken about the potential bacteria holding capacity of sponge filters compared to gravel, glass walls, rocks, etc.  I’ll attach a pic of a chart from aquariumscience.org that shows calculated surface areas of different media with effective surface area also shown (ceramic media does pretty poorly since the water flows around the pieces instead of through the actual ceramic).  This matches with estimates I’ve seen from other sources well before aquariumscience.org was ever a thing.  ACO sponge filters are very coarse, but likely still have more surface area and biofiltration capacity than gravel and certainly more than exists on bare glass walls that get cleaned fairly regularly, often weekly or even daily.

I have had ACO sponge filters that I haven’t cleaned since I set them up months ago, some need cleaning more often.  The Ziss air stones need the felt discs replaced about as often as the sponges need cleaning. They do clog sooner in filters that need cleaned more often.  Pre-filters on my HOB’s need cleaned more often since they have higher water flow through them, but it takes a lot to clog such coarse sponge and they’re pretty easy to clean.  Shrimp do love to graze on them.

As you can see, even 20 ppi sponge has almost double the effective surface area and 30 ppi has almost 3 times the surface area as typical aquarium gravel.  Flat, smooth, glass will have very minimal surface area in comparison.

[gardenman]

Just a nitrite spike would have me suspicious that the test kit/strip might be off a bit. Nitrite is the middleman of the nitrogen cycle. Ammonia becomes nitrites, which then become nitrates. Unless you've cleverly figured out a way to kill just the nitrite-oxidizing bacteria, that shouldn't happen. If the fish are acting fine and nothing seems "out of whack" I would assume a bad test result. 

As to the effectiveness of a clogged sponge filter, you have to ask what's clogging the filter? If it's a massive bacterial colony clogging the filter then it's going to be very effective as a filter even with reduced flow through the filter. Bacteria break down pretty much everything organic in the water, so anything "clogging" the filter is likely either food for bacteria or the bacteria themselves. I've never rinsed out a sponge filter and looked at what came out under a microscope, but my suspicion would be that much of what we're rinsing away are bacteria. Pretty much anything organic gets broken down by bacteria into something the bacteria need. Unless your filter is clogging up with fine sand or something similarly inorganic, much of what you're rinsing away when you clean the filter are bacteria. All that blackish gunk that comes out might be best left in.

And "clogging" a filter so there's no water flow at all, is pretty hard to do. (At least with a "normal" airflow. If you're using a powerhead it becomes easier.) I rarely clean my sponge filters and they work fine and mine are the finer pore, more likely to clog type. Speaking as someone who's tried to stop leaks from occurring in things that shouldn't leak, the idea of a sponge getting clogged enough to stop all water flow through it seems pretty remote. You can slow the flow of water through a sponge and if you're using a powerhead or powerful airstream that could cause the sponge to collapse in upon itself, but some water would still be finding its way through. Perhaps not enough to use the powerhead, but enough to keep the tank healthy.

[sumplkrum]

The sponge filters are good for quite a while before you have to clean them. You'll usually see algae starting to grow on them and that's a good sign it may be time to squeeze them out. I leave mine at least a month before messing with them.

If you're using the Ziss airstones, you may need to adjust them. The felt inserts do clog over time and reduce your airflow. Just loosen them up a little. Eventually you may need to replace the felt inserts (you get a few extra when you buy them).

If you're gravel vacing, that's probably just releasing extra gunck into the water and spiking the nitrites a little. Could also be over-feeding if there's only three fish.

Edited March 30, 2022 by sumplkrum

[nabokovfan87]

On 3/30/2022 at 3:30 AM, Odd Duck said:

I have had ACO sponge filters that I haven’t cleaned since I set them up months ago, some need cleaning more often.  The Ziss air stones need the felt discs replaced about as often as the sponges need cleaning. They do clog sooner in filters that need cleaned more often.

yeah, my issue for me was just trying to force too fine of a bubble. I haven't had to replace the felt, but simply clean it off.

 

 

On 3/30/2022 at 3:30 AM, Odd Duck said:

This matches with estimates I’ve seen from other sources well before aquariumscience.org was ever a thing.  ACO sponge filters are very coarse, but likely still have more surface area and biofiltration capacity than gravel and certainly more than exists on bare glass walls that get cleaned fairly regularly, often weekly or even daily.

Yeah, it's all dependent on what kind of a setup the tank has. I totally understand what you're saying. I was also referencing not just surface area, but the ability of the bacteria to populate with ease.  Some foam materials are very low friction, very smooth, others aren't. Plastic (or closer to that) would have a harder time sticking around but the bacteria that does would be stronger. If it's clogged, surface area doesn't really matter anymore and there is no flow / surface area for the bacteria to clean the water on.  Ceramic media, sintered glass media, sand vs. gravel substrate, there is a lot of variables that would cause better or worse sustainability long term.  Simply put, even if you're running sponge only, adding a bag of some half-decent ceramic media (or rocks) or something to sustain bacteria in a high flow region wouldn't hurt in this situation, especially with the OPs concerns.

But yeah, sponge absolutely works as proven 100000000x over and over with sustaining a colony to keep a tank thriving. There are variable for what is "best" and it's totally subjective in some of those variables (like air vs. pump).  Definitely interesting to see the chart you referenced, good little bit of knowledge to check out.

[Streetwise]

Only duckweed fully clogs my HoB sponges.

[BF McUmber]

To be clear my filter is not currently clogged. My airstone is bubbling away and I rinsed the filter out last weekend after a few days of getting positive nitrite results. Not much gunk came out when I did.  

I was more curious as to if a mulmy gunky filter that is still passing water through it would keep the beneficial bacteria going well. Or if there was a realm where the gunk suffocates out the bb like a coating of paint. Based on responses here it sounds like the BB will grow with the mulm just fine. 

 

On 3/30/2022 at 10:01 AM, gardenman said:

Just a nitrite spike would have me suspicious that the test kit/strip might be off a bit. Nitrite is the middleman of the nitrogen cycle. Ammonia becomes nitrites, which then become nitrates. Unless you've cleverly figured out a way to kill just the nitrite-oxidizing bacteria, that shouldn't happen. If the fish are acting fine and nothing seems "out of whack" I would assume a bad test result.

I thought the same thing initially, however I've had like 6 test strips comes back as positive. I tested my other two tanks at the same times and their strips came back negative. So I'm pretty sure I'm pregnant. I did put some fritz zyme 7 in but it was a bottle that was opened and like 4 months old. It has not helped so far.  

[modified lung]

@Odd Duck It's my turn to write an essay. 😁

Take that chart with a grain of salt. The guy from that website likes to throw around numbers from science papers without understanding the context behind them. 

For example "effective surface area" (a metric that isn't really used anymore with biofilters because it involves inventing non-existent surface area to make sense of faster nitrification rates than expected) is heavily dependent on many factors and varies widely between application and conditions.

The 600 effective surface area of fluidized K1 he lists is obviously from a wastewater management setting with ammonia concentrations that would kill any fish ...the higher the ammonia concentration the faster the nitrification rate and the higher the calculated "effective surface area". That number is impossible in an aquarium. Who knows where he got the rest of those numbers.

Or what size gravel? That makes a big difference. I'm not sure he realizes it but he seems to be referring to 1" gravel. Nobody uses that. In the water management literature K1, 1/4" gravel, and 1/2" lava rock are all considered to have the same specific (total or mathematical) surface area.

The advantage of K1 not being the surface area but (1) the massive void space which prevents clogging in situations with very high levels of suspended solids like a wastewater treatment plant (what K1 was originally made for) or a muddy pond or a farm where 20-30 kilograms of feed is thrown into a tank of sturgeon each day.

[Wrencher_Scott]

On 3/29/2022 at 9:53 PM, nabokovfan87 said:

The sponge is a very "poor" surface for bacteria but it does work.  You're going to have more bacteria on the rocks, sides, substrate, and surfaces of the tank.  If you're really concerned you can add a pile of lava stone, or media in a bag near the sponge and that can also help the tank to "seed" more bacteria.

 

Foam is a much better bio media then lava or most media in a bag like ceramic or Matrix. 

Also there not much BB on the tank surfaces. 

 

 

[Wrencher_Scott]

On 3/30/2022 at 5:10 PM, modified lung said:

@Odd Duck It's my turn to write an essay. 😁

Take that chart with a grain of salt. The guy from that website likes to throw around numbers from science papers without understanding the context behind them. 

For example "effective surface area" (a metric that isn't really used anymore with biofilters because it involves inventing non-existent surface area to make sense of faster nitrification rates than expected) is heavily dependent on many factors and varies widely between application and conditions.

The 600 effective surface area of fluidized K1 he lists is obviously from a wastewater management setting with ammonia concentrations that would kill any fish ...the higher the ammonia concentration the faster the nitrification rate and the higher the calculated "effective surface area". That number is impossible in an aquarium. Who knows where he got the rest of those numbers.

Or what size gravel? That makes a big difference. I'm not sure he realizes it but he seems to be referring to 1" gravel. Nobody uses that. In the water management literature K1, 1/4" gravel, and 1/2" lava rock are all considered to have the same specific (total or mathematical) surface area.

The advantage of K1 not being the surface area but (1) the massive void space which prevents clogging in situations with very high levels of suspended solids like a wastewater treatment plant (what K1 was originally made for) or a muddy pond or a farm where 20-30 kilograms of feed is thrown into a tank of sturgeon each day.

From what I remember he tested this HIMSELF in aquariums (that were not full of waist water, lol). I believe he fed the tanks with small amounts of ammonia over time. 

Did you read about the testing he did or just look at the chart? 

[Odd Duck]

On 3/30/2022 at 5:42 PM, BF McUmber said:

To be clear my filter is not currently clogged. My airstone is bubbling away and I rinsed the filter out last weekend after a few days of getting positive nitrite results. Not much gunk came out when I did.  

I was more curious as to if a mulmy gunky filter that is still passing water through it would keep the beneficial bacteria going well. Or if there was a realm where the gunk suffocates out the bb like a coating of paint. Based on responses here it sounds like the BB will grow with the mulm just fine. 

 

I thought the same thing initially, however I've had like 6 test strips comes back as positive. I tested my other two tanks at the same times and their strips came back negative. So I'm pretty sure I'm pregnant. I did put some fritz zyme 7 in but it was a bottle that was opened and like 4 months old. It has not helped so far.  

Your “gunk” IS your beneficial bacteria, along with some stuff they haven’t finished eating.  If you’re having nitrite spikes you may be rinsing too much.  You are probably rinsing away your bacteria.

On 3/30/2022 at 7:10 PM, modified lung said:

@Odd Duck It's my turn to write an essay. 😁

Take that chart with a grain of salt. The guy from that website likes to throw around numbers from science papers without understanding the context behind them. 

For example "effective surface area" (a metric that isn't really used anymore with biofilters because it involves inventing non-existent surface area to make sense of faster nitrification rates than expected) is heavily dependent on many factors and varies widely between application and conditions.

The 600 effective surface area of fluidized K1 he lists is obviously from a wastewater management setting with ammonia concentrations that would kill any fish ...the higher the ammonia concentration the faster the nitrification rate and the higher the calculated "effective surface area". That number is impossible in an aquarium. Who knows where he got the rest of those numbers.

Or what size gravel? That makes a big difference. I'm not sure he realizes it but he seems to be referring to 1" gravel. Nobody uses that. In the water management literature K1, 1/4" gravel, and 1/2" lava rock are all considered to have the same specific (total or mathematical) surface area.

The advantage of K1 not being the surface area but (1) the massive void space which prevents clogging in situations with very high levels of suspended solids like a wastewater treatment plant (what K1 was originally made for) or a muddy pond or a farm where 20-30 kilograms of feed is thrown into a tank of sturgeon each day.

Always a grain of salt with that website, but for the most part it jives with other sources from independent testing.  He certainly does sometimes have an odd mix of science and theory without necessarily differentiating between the two.  The issue is, that there is so little hard science that is readily available to the average aquarist.  This site gives people a starting place and explains things well enough that most people can grasp at least the basics and if they want to spring board from there, they can.  He’s rarely completely sideways on what he says even if he isn’t 100% correct.

[Ken Burke]

On 3/30/2022 at 5:30 AM, Odd Duck said:

@nabokovfan87, I think you may be mistaken about the potential bacteria holding capacity of sponge filters compared to gravel, glass walls, rocks, etc.  I’ll attach a pic of a chart from aquariumscience.org that shows calculated surface areas of different media with effective surface area also shown (ceramic media does pretty poorly since the water flows around the pieces instead of through the actual ceramic).  This matches with estimates I’ve seen from other sources well before aquariumscience.org was ever a thing.  ACO sponge filters are very coarse, but likely still have more surface area and biofiltration capacity than gravel and certainly more than exists on bare glass walls that get cleaned fairly regularly, often weekly or even daily.

I have had ACO sponge filters that I haven’t cleaned since I set them up months ago, some need cleaning more often.  The Ziss air stones need the felt discs replaced about as often as the sponges need cleaning. They do clog sooner in filters that need cleaned more often.  Pre-filters on my HOB’s need cleaned more often since they have higher water flow through them, but it takes a lot to clog such coarse sponge and they’re pretty easy to clean.  Shrimp do love to graze on them.

As you can see, even 20 ppi sponge has almost double the effective surface area and 30 ppi has almost 3 times the surface area as typical aquarium gravel.  Flat, smooth, glass will have very minimal surface area in comparison.

I don’t put a lot of credence in this table.  IMO, there are a lot of variables that impact the ability for a “filter” to break down ammonia, and focusing on one factor provide misleading results.  
 

Any surface area in the aquarium can support bb, but before it becomes an effective filter water needs to flow over it.  What makes sponge filters so effective is a) water pulled through the sponge bringing nutrients to the bb and b) the rising bubbles keep the water moving past the other surfaces.  
 

The surface area of the substrate is huge, but unless you are running a ugf much of that surface area has little to no water flow to bring the ammonia or nitrite to the bb.  
 

of course I could be way off, and it wouldn’t be the first time today. but if the bacteria aren’t swimming through the water column to get nutrients, the water needs to bring the nutrients to them.

 

 

 

 

 

 

 

[nabokovfan87]

On 3/30/2022 at 5:10 PM, modified lung said:

For example "effective surface area" (a metric that isn't really used anymore with biofilters because it involves inventing non-existent surface area to make sense of faster nitrification rates than expected) is heavily dependent on many factors and varies widely between application and conditions.

I reference this just to demonstrate the point.

Again, not going to say go buy biohome or anything, but media definitely comes in various qualities and there is good and bad. There is a logic behind what works well and why. We are talking about aerobic not anaerobic bacteria which is a pretty "easy" thing to grow. More oxygen feeds that bacteria. A clogged filter doesn't as well as a clean one. And for someone having issues with how clogged is clogged.... See some of the videos posted above for filters that have been ran for far too long between cleaning. Sponge is generally regarded as a means to remove much, not specifically for bacterial growth in every single use. Yes, there is sponge filters, that's what we are talking here. I'll go back to my point about (just like ceramic media) there is a difference in media quality, be it sponge or anything else. Certain materials and production methods mean different variables.

Edited March 31, 2022 by nabokovfan87

[Widgets]

On 3/30/2022 at 10:21 PM, Ken Burke said:

I don’t put a lot of credence in this table.  IMO, there are a lot of variables that impact the ability for a “filter” to break down ammonia, and focusing on one factor provide misleading results.  
 

Any surface area in the aquarium can support bb, but before it becomes an effective filter water needs to flow over it.  What makes sponge filters so effective is a) water pulled through the sponge bringing nutrients to the bb and b) the rising bubbles keep the water moving past the other surfaces.  
 

The surface area of the substrate is huge, but unless you are running a ugf much of that surface area has little to no water flow to bring the ammonia or nitrite to the bb.  
 

of course I could be way off, and it wouldn’t be the first time today. but if the bacteria aren’t swimming through the water column to get nutrients, the water needs to bring the nutrients to them.

I agree with your points, but according to the testing details on the website, the numbers in the efficiency column are from his tests using an air driven box filter. Even keeping the air pressure the same, the nature of the media and how it restricts water flow through the filter will impact the test. While that restriction may not be directly related to surface area, it is part of the measure of efficiency. 

Like everything else on the internet, we must be smart consumers, think for ourselves and do our own followup research.

[modified lung]

On 3/30/2022 at 5:38 PM, Wrencher_Scott said:

From what I remember he tested this HIMSELF in aquariums (that were not full of waist water, lol). I believe he fed the tanks with small amounts of ammonia over time. 

Did you read about the testing he did or just look at the chart? 

Of course I read it. Ammonia + water is considered waste water. For example, fish waste water. I don't want to get into an argument or anything but basically, he shows what worked for certain conditions and a certain application while unaware of important variables while using shoddy methodology and non-standard math then makes very firm, broad generalizations that don't follow, then at least seems to contradict himself. It's a pattern he repeats all over the website.

Sorry if that guy annoys me more than he should. He kinda hits all my buttons.

On 3/30/2022 at 6:29 PM, Odd Duck said:

On 3/30/2022 at 3:42 PM, BF McUmber said:

To be clear my filter is not currently clogged. My airstone is bubbling away and I rinsed the filter out last weekend after a few days of getting positive nitrite results. Not much gunk came out when I did.  

I was more curious as to if a mulmy gunky filter that is still passing water through it would keep the beneficial bacteria going well. Or if there was a realm where the gunk suffocates out the bb like a coating of paint. Based on responses here it sounds like the BB will grow with the mulm just fine. 

 

I thought the same thing initially, however I've had like 6 test strips comes back as positive. I tested my other two tanks at the same times and their strips came back negative. So I'm pretty sure I'm pregnant. I did put some fritz zyme 7 in but it was a bottle that was opened and like 4 months old. It has not helped so far.  

Expand  

Your “gunk” IS your beneficial bacteria, along with some stuff they haven’t finished eating.  If you’re having nitrite spikes you may be rinsing too much.  You are probably rinsing away your bacteria.

On 3/30/2022 at 5:10 PM, modified lung said:

@Odd Duck It's my turn to write an essay. 😁

Take that chart with a grain of salt. The guy from that website likes to throw around numbers from science papers without understanding the context behind them. 

For example "effective surface area" (a metric that isn't really used anymore with biofilters because it involves inventing non-existent surface area to make sense of faster nitrification rates than expected) is heavily dependent on many factors and varies widely between application and conditions.

The 600 effective surface area of fluidized K1 he lists is obviously from a wastewater management setting with ammonia concentrations that would kill any fish ...the higher the ammonia concentration the faster the nitrification rate and the higher the calculated "effective surface area". That number is impossible in an aquarium. Who knows where he got the rest of those numbers.

Or what size gravel? That makes a big difference. I'm not sure he realizes it but he seems to be referring to 1" gravel. Nobody uses that. In the water management literature K1, 1/4" gravel, and 1/2" lava rock are all considered to have the same specific (total or mathematical) surface area.

The advantage of K1 not being the surface area but (1) the massive void space which prevents clogging in situations with very high levels of suspended solids like a wastewater treatment plant (what K1 was originally made for) or a muddy pond or a farm where 20-30 kilograms of feed is thrown into a tank of sturgeon each day.

Expand  

Always a grain of salt with that website, but for the most part it jives with other sources from independent testing.  He certainly does sometimes have an odd mix of science and theory without necessarily differentiating between the two.  The issue is, that there is so little hard science that is readily available to the average aquarist.  This site gives people a starting place and explains things well enough that most people can grasp at least the basics and if they want to spring board from there, they can.  He’s rarely completely sideways on what he says even if he isn’t 100% correct.

I disagree with that. In almost everything on there I've read he's usually right enough in a certain irrelevant context that if you search him on it, you won't find he's dangerously wrong unless you do some serious digging. It's the worst kind of misinformation IMO.

[Odd Duck]

On 3/31/2022 at 12:37 AM, modified lung said:

Of course I read it. Ammonia + water is considered waste water. For example, fish waste water. I don't want to get into an argument or anything but basically, he shows what worked for certain conditions and a certain application while unaware of important variables while using shoddy methodology and non-standard math then makes very firm, broad generalizations that don't follow, then at least seems to contradict himself. It's a pattern he repeats all over the website.

Sorry if that guy annoys me more than he should. He kinda hits all my buttons.

I disagree with that. In almost everything on there I've read he's usually right enough in a certain irrelevant context that if you search him on it, you won't find he's dangerously wrong unless you do some serious digging. It's the worst kind of misinformation IMO.

Until I find a single, readily available resource, that can explain the basics better with more accuracy, then I’ll still aim people at his site as a starting place.  If you have a better suggestion, I’m all ears.  ACO’s information is harder to access because of how it’s spread out and divided up.  The hobby desperately needs a single source/website that holds all the basics, plus more advanced info in an organized, more searchable format with easy links to move from one topic to the next.

If you can point out a website like that for me that’s more reliable and accurate, I’m all ears.

[Wrencher_Scott]

On 3/30/2022 at 7:36 PM, nabokovfan87 said:

I reference this just to demonstrate the point.

Again, not going to say go buy biohome or anything, but media definitely comes in various qualities and there is good and bad. There is a logic behind what works well and why. We are talking about aerobic not anaerobic bacteria which is a pretty "easy" thing to grow. More oxygen feeds that bacteria. A clogged filter doesn't as well as a clean one. And for someone having issues with how clogged is clogged.... See some of the videos posted above for filters that have been ran for far too long between cleaning. Sponge is generally regarded as a means to remove much, not specifically for bacterial growth in every single use. Yes, there is sponge filters, that's what we are talking here. I'll go back to my point about (just like ceramic media) there is a difference in media quality, be it sponge or anything else. Certain materials and production methods mean different variables.

IMO what people miss about this fancy media is as soon as it builds BB it plugs up, then you basically have a piece of non-porous rock that defeats the whole purpose of how great is is supposed to be in the first place. That's why foam is so good. 

p.s. This pondguru guy doesn't seem to get this point one bit, he doesn't have a clue. 

Edited March 31, 2022 by Wrencher_Scott

[Wrencher_Scott]

On 3/30/2022 at 10:37 PM, modified lung said:

Of course I read it. Ammonia + water is considered waste water. For example, fish waste water. I don't want to get into an argument or anything but basically, he shows what worked for certain conditions and a certain application while unaware of important variables while using shoddy methodology and non-standard math then makes very firm, broad generalizations that don't follow, then at least seems to contradict himself. It's a pattern he repeats all over the website.

Sorry if that guy annoys me more than he should. He kinda hits all my buttons.

I disagree with that. In almost everything on there I've read he's usually right enough in a certain irrelevant context that if you search him on it, you won't find he's dangerously wrong unless you do some serious digging. It's the worst kind of misinformation IMO.

You referred to waist water at water treatment plants with super high ammonia, not water with a small amount of ammonia. 

He actually tested these media types in 5 gallon buckets with corner filters.

As for media surface area he says this:

 Because of reticulation and free volume considerations the surface area calculations are not very dependable. Extrapolating from the testing and giving aquarium gravel the most dependable surface area calculation, gives the following “effective surface area” by media. This is the surface area which should be used for calculating the required volume of filter media for a given weight of fish.

That's why I asked if you read it. And I don't want to argue either, we are free to believe what we want, so I'm done with this. Happy fish keeping. 

[StanF]

Getting back on topic...

I have a medium coop sponge filter and an intake prefilter on my HOB.  I clean them maybe every couple of months.  They don't seem to clog at all for me.  My goldfish do a great job of cleaning the outside of the filters, so I'm sure that helps.

I also have my HOB filled with pinky floss which catches the small stuff and "polishes" the water.  The pinky filters get replaced every few weeks because they eventually get clogged with waste and mulm.

StanF