CARBON INSERT

[Dare On]

Other than making the water nice and clear, what else does a carbon filter do to the water in your aquarium?

 

[luxum]

It removes certain types of impurities such as residue from medications, and organic impurities that cause that swampy smell that tanks sometimes get, or tea colored stains from driftwood. Most people agree that carbon is not needed all the time in a healthy aquarium, but only now and then for a specific need, like to remove meds after treatment, to remove the smell for a week or so when your mother-in-law is coming to visit, things like that. Carbon is said to remove some substances that live plants use, and there is an old word of mouth belief that carbon can sometimes leach the stuff it already absorbed back into the tank, but i don't really understand how that could happen and have never seen any proof. What is sure is that carbon has a very short effective life span, 1 or 2 weeks, and if you leave it in longer than that it basically becomes biomedia for all intents and purposes.

 

[Dare On]

luxum: Thanks very much for the information.

 

[Bling]

I read somewhere that you're never supposed to use carbon for saltwater. Do you know why that would be? Or maybe I misunderstood. Thanks!

 

[FishDan]

I read somewhere that you're never supposed to use carbon for saltwater. Do you know why that would be?

I believe it is due to the carbon's ability to remove many trance minerals and chemicals needed, especially for corals and inverts in a SW tank.

and there is an old word of mouth belief that carbon can sometimes leach the stuff it already absorbed back into the tank, but i don't really understand how that could happen and have never seen any proof.

I can't happen. Carbon does not absorb anything. It adsorbs. Adsorption (basically) is a chemical process. The impurities carbon removes from the water are chemically bonded to the carbon. Once this happens the only way to break these bonds is by heat. A lot of it. There is no way your aquarium will get this hot. Once the chemicals are adsorbed, they can not "leach" back into your water. The closest thing that can happen is that the chemicals bypass the carbon and recirculate. This happens once your carbon has adsorbed all it can. Carbon can last for longer than 2 weeks, but it all depends on how "impure" your water is. For example, if you added bottled water or pre-filtered water (like with a Brita faucet adapter) your carbon will last much longer, as the carbon in the Brita or at the bottled water plant has removed most of the impurities already. Of course they also remove many trace elements that may be needed in your aquarium. Especially if you keep live plants.

\Dan

 

[Eelzor]

I use carbon all the time in my freshwater and for years to come. The ONLY negatives I have ever heard about carbon is that in saltwater aquariums, it may reduce the fishes colour, but like they say, never beleive the internet.

 

[luxum]

Thanks Fishdan, it has always seemed like an urban legend when i think back to chemistry 101, i could never figure out how that could possibly happen.

 

[Bol]

It's my understanding that the adsorption process is somewhat reversible under aquarium conditions, and it is possible that carbon will release a molecule that it has adsorbed ... if it encounters another molecule for which it has a greater affinity; in which case the original molecule can become displaced. But under aquarium conditions this can/will happen (statistically) infrequently, and at a very slow rate, so that the "toxin dump" people fear when they hear the word "leach" is nearly impossible.

 

[K-Holed]

Here's a nice little link regarding carbon.

Carbon Infomation