# Over flow question



## Mean Harri (Dec 14, 2009)

Hi all. I've been reading up on SW FOWLR and it sounds like something I'd like to try one of these days in the future. It may be awhile though. I was curious though. I've concluded from reading that about the only filtration needed is a protein skimmer and the live rock/live sand. So why does one need the over flow and sump? Is it to collect the water to feed to the sump? Is it to house charcoal? 

Thanks for clarifying.


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## Pasfur (Mar 29, 2008)

A sump is generally used on aquariums over 55 gallons, because most of the efficient protein skimmer designs are best used with a sump. The sump allows you to skim organics from the surface of the water, which then fall into the sump, and are pumped into the skimmer. The sump also allows for the use of baffles to control the water level in different areas of the sump, which allows for a consistent height of the water inside the protein skimmer. This allows for a more consistent skimmer output. 

In addition to filtration advantages, the sump has visual appeal. It allows a place for the skimmer, heater, carbon, UV Sterilizer, and even refugium to be placed out of view of the display. This also allows for easier access to this equipment, as opposed to having it all hang on the back of the tank. Additionally, the tank can be placed near flush to the wall.

If you were to choose an aquarium of 55 gallons or smaller, there are many efficient skimmers that are designed with an overflow box included, allowing for surface skimming of organics in a hang on model. For these size aquariums, I think this is the easiest option for most people.


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## Mean Harri (Dec 14, 2009)

Thanks Pasfur. I see I made a typo in one of my questions. IS it to collect water to feed a _skimmer_ is what it should read.


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## Pasfur (Mar 29, 2008)

Mean Harri said:


> Thanks Pasfur. I see I made a typo in one of my questions. IS it to collect water to feed a _skimmer_ is what it should read.


A protein skimmer removes organic waste directly from the water column. Organics tend to bond at areas where air and water meet, such as the water surface. This is what forms the film that accumulates at the surface of saltwater systems without overflows.

If you use an overflow to a sump, or an overflow box, then the area within the water where the majority of organics tend to accumulate is being fed into the skimmer, making the skimmer more efficient in removing organics.


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