View Full Version : this might be a silly question

02-02-2003, 07:28 PM
ok.... so what exactly does this carbon in my filter do anyways... <i> and</i> how often should i be changeing it?

02-02-2003, 09:14 PM
No question is ever stupid! This is info I'm giving you is based on reading various books on fishkeeping and personal experience. Others will, I hope, comment on your post.

Without getting too technical, carbon is used for various reasons in an aquarium. It is supposed to remove some chemicals and other contaminants from the water. Because of the carbon atom's crystalline structure, it has a large surface area and can thereby enhance the purification of the water. It is especially useful to put new activated carbon in a filter after a course of medication, since it helps any traces of the med to bond to the carbon's surface and thus remove it from the water. That carbon should then be discarded. Carbon also helps in reducing the unpleasant odors that aquarium water can take on. Carbon can be recharged, but it requires such great temperatures that the aquarist cannot accomplish this at home.
So basically what it boils down to is this: [i:5adfd5c36e]Carbon sucks bad stuff out of the water and helps the water to stay clear.[/i:5adfd5c36e]
Now here is something else to consider...carbon's true effectiveness is lost soon after you put it in your filter (in maybe about 3-4 days). This is why some people don't believe in using it.
I use it and have always used it. (I had an aquarium in my room, and one in the family room when I was a teenager too! My mother hated it also! :roll: She appreciates it now though, when she comes to my house and sees my tank. :D Luckily I had a father who loved fish and still does.)
I usually change my carbon once a month, though not at the same time in both filters I run on my tank.

Hope this was helpful!

Cichlid Jeans
02-03-2003, 10:19 AM
Good info in Merlyn's post. Another approach:

1. Is it necessary to use carbon?

2. Does it do any good to use carbon?
Carbon removes chemicals from your tank water which can't be converted by biological filtration, and which can't be trapped by any other mechanical filter, not even a diatom filter.

Lots of inexpensive filter systems -- Aquaclear and Penguin, for example -- use carbon as both a molecular and mechanical filter component: pouches of carbon are used to remove particulates which the foam or sponge part of the filtration setup can't trap. The carbon clarifies the water dramatically in the first day or so -- it's quite the fix.

3. Can it do any harm to use carbon?
As Merlyn pointed out, carbon will strip out medication compounds, so it needs to be removed before you start treating the tank for ich or whatever. Carbon will also strip out trace elements which planted aquaria need, so you may end up having to replace them with fertilizer. I personally think cichlids need those trace elements as well -- hey, I'm no biologist, but I've heard cichlids live in nature.

My conclusion: I use carbon in a Magnum 350 to get rid of medication after a treatment program, if I think it is still a problem. I don't use it otherwise. In particular, I don't use filters that depend on carbon: they have to be able to do a satisfactory job without it, or I'll get something else, because I don't want carbon in there all the time.

For water polishing, I think you can't do better than the Magnum 350 with paper cartridge, or the Vortex diatom filter.