Skimmer Sizing With a Roller Filter: Effective Tank Volume Reduction

[dudedudedude]

Apologies if this isn’t the right place to post — I’m new to roller filters and understand that they reduce the organic load presented to a protein skimmer. What I haven’t been able to find is any discussion of the magnitude of this effect. Specifically, I’m curious whether the community has an intuitive or experience-based estimate for how much a roller filter effectively reduces skimmer demand.
Conceptually, I’m thinking of it like this:


Effective Tank Volume (skimmer + roller) = Tank Volume (skimmer only) × X


where X represents the fractional reduction in effective skimming load due to the roller filter.


I realize this depends heavily on factors like stocking, feeding, roller efficiency, and flow, so I’m not expecting a precise number — just a ballpark range. For example, do people tend to think in terms of something like a 15–25% reduction, or is it typically larger or smaller in real-world systems?


Any firsthand experience or rules-of-thumb would be greatly appreciated.

 

[Randy Holmes-Farley]

I would not recommend any change to skimmer size based on using or not using a roller mat.

Roller mats will not reduce dissolved organics, which is an important part of what skimmers remove. These include all of the active biological toxins that organisms release, and all of the compounds that cause yellowing of the water.

Skimmers also provide important aeration, and I'd use a skimmer even if all it did was aerate.

 

[rishma]

I would not recommend any change to skimmer size based on using or not using a roller mat.

Roller mats will not reduce dissolved organics, which is an important part of what skimmers remove. These include all of the active biological toxins that organisms release, and all of the compounds that cause yellowing of the water.

Skimmers also provide important aeration, and I'd use a skimmer even if all it did was aerate.

I see it a little differently. I think there’s some logic to using a smaller skimmer if using a roller mat. I agree that the roller mat removes something different than the skimmer, but I would argue that the roller mat removes some materials that would otherwise breakdown into components that the skimmer does remove. By removing them first with the roller mat, a smaller skimmer might be appropriate for what remains.

All that said, I don’t use mechanical filtration, nor do I think there is a practical method to determine skimmer size with or without roller mat. But a smaller skimmer with a roller mat is logical. Skimmers that are too big for the amount of organics in the water to not function well other than being good at aeration.

 

[Randy Holmes-Farley]

All that said, I don’t use mechanical filtration, nor do I think there is a practical method to determine skimmer size with or without roller mat.

That’s reasonable, and I especially agree, with that last bit. Using manufacturer gallon ratings to compare skimmers seems rather prone to bias. lol

 

[dudedudedude]

I guess one thing to look at is if anyone that had a well matched skimmer to their tank had to get a smaller skimmer once a roller filter was added

 

[Randy Holmes-Farley]

I personally have never looked for such info, but also never heard of anyone doing it.

 

[dudedudedude]

I have read about some poeple in the past needing to downsize there skimmer cause they just didnt have enough waste anymore for stable foam. I think this was more an issue with adding a roller filter to a system with a wider neck skimmer

 

[Randy Holmes-Farley]

I've not heard that, and I'd be skeptical. While the effect Rishma notes is likely real (reduced dissolved organics after removing particulate organics), I just don't think it likely to be big enough to impact the optimal size of a skimmer. The caught particles themselves are not going to help make a foam. Only dissolved organics can do that. Particles may get into the foam and be skimmed out, but they themselves cannot foam.

 

[Dan_P]

Apologies if this isn’t the right place to post — I’m new to roller filters and understand that they reduce the organic load presented to a protein skimmer. What I haven’t been able to find is any discussion of the magnitude of this effect. Specifically, I’m curious whether the community has an intuitive or experience-based estimate for how much a roller filter effectively reduces skimmer demand.
Conceptually, I’m thinking of it like this:


Effective Tank Volume (skimmer + roller) = Tank Volume (skimmer only) × X


where X represents the fractional reduction in effective skimming load due to the roller filter.


I realize this depends heavily on factors like stocking, feeding, roller efficiency, and flow, so I’m not expecting a precise number — just a ballpark range. For example, do people tend to think in terms of something like a 15–25% reduction, or is it typically larger or smaller in real-world systems?


Any firsthand experience or rules-of-thumb would be greatly appreciated.

Skimming stops when the foam forming chemicals drops to a level where persistent foam does not exist. Using a skimmer that is too big for a system just means you reach that point sooner. Too small likely means you can never reach that point of reduction

 

[Phamousreef]

Since we all are in the topic of roller mat and skimmer, is it more ideal to have the flow faster or slower going through the roller mat for better removal of all the waste? Does having a slower turn over rate helps with better filtration for the roller mat and protein skimmer?

 

[Randy Holmes-Farley]

Since we all are in the topic of roller mat and skimmer, is it more ideal to have the flow faster or slower going through the roller mat for better removal of all the waste? Does having a slower turn over rate helps with better filtration for the roller mat and protein skimmer?

If you want maximum removal of particulates, then more water filtering through the filter would seem to be the way.

I am not convinced particulate removal is always desirable and I don’t do it, but I know that many folks do. :)