Are mechanical filtration contraproductive?

[JonasRoman]

I've been thinking about this for quite some time, and my conclusions are based on empirical experience. In my most recent systems, I have completely eliminated all forms of mechanical filtration. What I’ve observed as a result is that the water has been—and continues to be—absolutely crystal clear, with very few visible particles.

At first, this might seem counterintuitive. One would expect the opposite. But I believe that by not removing the fine particles that are naturally present in any aquatic environment, these particles actually help polish the water.

We know, for example, that bentonite clay or even the addition of crushed limestone can have similar clarifying effects.

Therefore, I would argue that systems using fully automatic filter mats—such as the RollerMat and similar solutions—are counterproductive in getting crystal clear water. I’ve seen many such setups, and I can’t say the water in those systems is particularly clear.

My system at the moment uses no filter socks, no ozone, no activated carbon—and water is like the fish are swimming in air. Again, I believe the mechanism here is that the particles I allow to remain in the water have a sort of polishing effect. They seem to bind organic matter and help clarify the water naturally.

Your experience?

/Jonas

 

[Sean Clark]

I ran my established tank for about 6 months without mechanical filtration and couldn't really tell the difference over time... Until I put the mechanical filtration back on and then I noticed a huge improvement in my water. Floating in air clean. I'll keep my mechanical filter.

 

[ColorMeGone]

I have never used any kind of filtration in my nano. If for some reason I have to stir things up I will run a bit of floss for a few hours.

 

[Hakon]

I think it would probably depend on a lot of factors unique to any given tank. I definitely think that more rock work and natural surface is better than artificial media but I held that opinion ten years ago too. It also might depend on how polished the water is to start with and what kind of nutrient load you're working with, a lot of the stuff that skimmers and mechanical filters pull out is just excess microflora and algae in the water column, if you're dialed in enough to not have a lot of that it may be that mechanical filtration is just not as necessary, conversely in someone else's tank where they're having trouble keeping the load down they might be more necessary.

 

[vlangel]

I like a heavy fish load as they are my 1st love. I have a fair amount of very mature live rock, sand, coral and ornamental macroalgae so biologically a lot of the produced nutrients is then taken up and utilized. Still, I have a HOB Aquaclear filter to put live rubble rock in the chamber to be a safe haven for pod proliferation. If the water needs a little polishing then floss and carbon can easily be added and of course water changes.

 

[Freenow54]

I've been thinking about this for quite some time, and my conclusions are based on empirical experience. In my most recent systems, I have completely eliminated all forms of mechanical filtration. What I’ve observed as a result is that the water has been—and continues to be—absolutely crystal clear, with very few visible particles.

At first, this might seem counterintuitive. One would expect the opposite. But I believe that by not removing the fine particles that are naturally present in any aquatic environment, these particles actually help polish the water.

We know, for example, that bentonite clay or even the addition of crushed limestone can have similar clarifying effects.

Therefore, I would argue that systems using fully automatic filter mats—such as the RollerMat and similar solutions—are counterproductive in getting crystal clear water. I’ve seen many such setups, and I can’t say the water in those systems is particularly clear.

My system at the moment uses no filter socks, no ozone, no activated carbon—and water is like the fish are swimming in air. Again, I believe the mechanism here is that the particles I allow to remain in the water have a sort of polishing effect. They seem to bind organic matter and help clarify the water naturally.

Your experience?

/Jonas

I stopped using filter socks a while ago. I do use batting used in the sewing hobby as well as a Marineland multi purpose water polisher that you can add Demetrious earth to if you want. I particularly like it as I can direct its flow for my Coral. I give it all the credit for keeping my water clean. Also a Canister filter with various media. I certainly cant argue with success but tough to change my ways. I could try it I guess no harm no foul

 

[Thales]

I think regular use of mechanical filtration is not needed in most reef tanks and actually doesn't do much except make the reefer feel like something has happened.
I stopped regular use of filter socks, both at home at at the Steinhart Aquarium in about 2012, and see no reason to run it 'just because'

 

[JonasRoman]

Interesting with different experiences and views on this

 

[Freenow54]

I think it would probably depend on a lot of factors unique to any given tank. I definitely think that more rock work and natural surface is better than artificial media but I held that opinion ten years ago too. It also might depend on how polished the water is to start with and what kind of nutrient load you're working with, a lot of the stuff that skimmers and mechanical filters pull out is just excess microflora and algae in the water column, if you're dialed in enough to not have a lot of that it may be that mechanical filtration is just not as necessary, conversely in someone else's tank whe

re they're having trouble keeping the load down they might be more necessary.

With the Marineland water polisher I can wait three weeks before cleaning glass

 

[p1u5h13r4m24]

Every tank is different. For me a roller Matt was too much. However I still prefer to keep my tank as clean as possible and water changes do it for me

 

[Freenow54]

Here is mine.

 

[Randy Holmes-Farley Verified Community Expert]

I cannot make comparisons on my tanks since I have never wanted or used any
mechanical filtration except in unusual situations for short periods of time (such as possible dinos).

 

[FranklinDattein]

I’ve used roller mats across several tanks on and off, and honestly, I haven’t seen any noticeable difference in overall water clarity or the amount of visible particulates.


That said, I’ve noticed a few practical benefits:
- When fish disturb the substrate, particulates clear up much faster, usually within 5 minutes instead of 30.
- The system seems to handle a smaller skimmer without sacrificing nutrient control.
- It adds some peace of mind when dosing lanthanum chloride, since it helps catch any precipitate that forms.

 

[JumboShrimp]

Lol! I've used sulfur denitrators, skimmers, large UV sterilizers, algae scrubbers, etc., etc., but for $15-bucks, this is my best pound-for-pound secret weapon:

 

[JonasRoman]

Some comment above was that living "materia" like rocks etc have a cleaning effect on the water. I agree and that strength my theory that biological particles in water have a polishing effect. I belive these organic particles (but inorganic aswell) absorb even smaller particles making water crystal clear.

We have all noticed that if you stirr the sand , initially ofckurse cloudy water but after X hours it's crystal clear, more than before. It's the same effect and mechanism.

/Jonas

 

[Freenow54]

I cannot make comparisons on my tanks since I have never wanted or used any
mechanical filtration except in unusual situations for short periods of time (such as possible dinos).

I am interested to know your approach then if you don't mind sharing

 

[FranklinDattein]

Some comment above was that living "materia" like rocks etc have a cleaning effect on the water. I agree and that strength my theory that biological particles in water have a polishing effect. I belive these organic particles (but inorganic aswell) absorb even smaller particles making water crystal clear.

We have all noticed that if you stirr the sand , initially ofckurse cloudy water but after X hours it's crystal clear, more than before. It's the same effect and mechanism.

/Jonas

I don't think the clearing effect has anything to do with sand being bio-active ("Biological particles").
It is more likely the reaction is the same as when "Coral Snow" (calcium carbonate dust) is dosed. The CaCo3 particles are slightly positively charged and attract negatively charged colloids, thus causing precipitation by flocculation.

 

[Thales]

I cannot make comparisons on my tanks since I have never wanted or used any
mechanical filtration except in unusual situations for short periods of time (such as possible dinos).

Hey Randy!

Are you aware of any studies on how quicking biological matter breaks down in our tanks and on the reef? I imagine it is very fast, which is one of the reasons I don't use much mechanical filtration, but when I look I can only find vague references to 'hours or days'. Any ideas? :D

 

[mcarroll]

Hey Randy!

Are you aware of any studies on how quicking biological matter breaks down in our tanks and on the reef? I imagine it is very fast, which is one of the reasons I don't use much mechanical filtration, but when I look I can only find vague references to 'hours or days'. Any ideas? :D

Not Randy, but I think this addresses the topic in the detail you're looking for, but happens to focus on everyone's favorite pest "algae", Dino's. (It does not specifically address tank life, but still is worth look IMO.)

The role of nutrients in decomposition of a thecate dinoflagellate.

That may not be satisfying even though they get to specific numbers that you can infer quite a bit from (see the magnitude of nutrients that get consumed on the way out of a dino bloom)....I think if you feed this title into Google Scholar and look at related articles you'll find a lot more.

 

[JonasRoman]

I don't think the clearing effect has anything to do with sand being bio-active ("Biological particles").
It is more likely the reaction is the same as when "Coral Snow" (calcium carbonate dust) is dosed. The CaCo3 particles are slightly positively charged and attract negatively charged colloids, thus causing precipitation by flocculation.

Exactly