# Filter layers question



## darkfalz (May 7, 2006)

Over my main aquarium there's a large unit which holds a spray bar which filters water through three layers, originally

1. Carbon cartridge with carbon pellets and white foamy stuff on top
2. Coarse black foam
3. Ceramic noodles

This is the order from the aquarium manual.

As the carbon cartridges are relatively expensive and hard to come by, instead I have a small bag of carbon in the bottom layer with the ceramic noodles, and have just been using cut filter foam pads on top.

My question is that it seems illogical to me to have the fine white filter on top of the coarse black foam. Shouldn't it go through the coarse one first to catch the larger particles, then the finer foam to catch the finer ones? Am I crazy? The only thing is that the white top foam is the one I'd be rinsing most often, and it doesn't last nearly as long as the strong coarse black foam. This foam is made of the same material as the main (and only) medium in my 40L internal filter, so it obviously support bacteria colonies.

What do you think? How does it work in cannister filters?


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## Guest (Feb 24, 2008)

which brand? depending on the filter and the way the water runs through the media, you do different things.

IMO, in general, the first thing the water should run through is the coarsest sponge, then a finer sponge, then bio media, then carbon (if you want to use it, i dont), and finally a polish pad (the white pad)

that seemed to work best for me, the large stuff is caught first, that way you odnt clog up your bio media, then lastly the fine pad polishes the water before going into the tank, making it all sparkley and preeeeeettyyy.


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