Filter Media Opinions Please

[stoneagedinosaur]

Hi all

Currently running an Aqua One Aquastyle 850 with stock filtering (two trays over the top of the tank with water passing through - Carbon and Wool Cartridge then Sponge Pad then finally through BioNood Ceramic Cylinders) The cartridge has been in for about 8 weeks and the manufacturer reckons it needs replacing but I am unsure about using carbon in the tank.

Lots of threads warn against using carbon and I've seen it suggested to cut open the wool on the top cartridge, take out the carbon and replace with some Bio media instead. Any tips / suggestions here?

Also, whilst trawling the net, I have come across Advance Sub Sintered Glass Biological Filter Media as a replacement for the ceramic noodles. Anyone use this? Is it any good? How do I replace these for the ceramic noodles without triggering a new cycle?

Am I worrying too much???

Why is carbon so bad in tanks any how?

Cheers

 

[waterdrop]

Carbon isn't bad at all, its just "optional." Its a bit of a complicated story, some is that its just expensive and not practical and some of its that its not ideal for the job.

Of the three functions of filtration, biological, mechanical and chemical, carbon is meant to satisfy the "chemical" function. It "adsorbs" (attracts chemicals via charge rather than trapping them.) The problem is that on average it only does this for at most about 3 days and then is ready to be pulled out, tossed and replaced with fresh carbon. Who do you know who is going to actually do this?

It turns out the main good uses for carbon are to remove medicines (its number one use), to remove tannins (the yellow tea from bogwood etc.) and finally, to sometimes remove organic smells of unknown origin. So carbon has an important place on the aquarist's storage shelf. You should definately have some around. On the other hand, there's no need to be spending the money to have it in there all time and be replacing it every week either.

All types of filter media overlap in function. All types will do some of the mechanical function (trapping particles and debris) but some will do it better than others. Carbon can be "fair" at both mechanical and biological (in addition to its primary role of chemical filtration) but that's really not good enough to justify having it taking up space. In both of those non-chemical roles, one of the reasons carbon is not so good is that it gradualy crumbles and breaks down, allowing debris to escape or bacteria to leave the filter and be removed at water changes. Other media don't have this problem. Ceramic rings are good at both "randomizing" the incoming water streams (to slow it down and allow larger debris particles to drop out before they would clog the next smaller media coming up) and at being a great surface for bacteria. They last forever! Ceramic gravel is a great "middle size mechanical particle catcher layer" as it too lasts forever and provides outstanding bacterial surfaces. Sponge is also fantastic as both a biological and a mechanical media, although lasting fewer years than ceramics, but it also can have higher surface area for the bacteria, so its very competitive with ceramic for the title of "best." There are also plastic doodads often called "bioballs" (or other shaped plastic things) but these are a special case, better used for huge "sump" filters where you can put so many that you still get a good volume of surface area but couldn't afford the more expensive ceramic equivalents.

~~waterdrop~~

 

[stoneagedinosaur]

Cool

So what's the best set up for filtration media then. Open to all...

 

[waterdrop]

It depends on your particular filter, both because of the media volume of the filter and other "features." I'm not familiar with your filter so I'll defer to someone who is. If no one comments I'll be happy to make some more general statements.

~~waterdrop~~