water change problem!

[Calihawk]

Buy some activated Carbon, wrap it up in mesh bags and sink it in tank, Voila. Takes care of Chlorine and Chloramine. Carbon just cannot do Nitrate/Nitrite

 

[mshill90]

Buy some activated Carbon, wrap it up in mesh bags and sink it in tank, Voila. Takes care of Chlorine and Chloramine. Carbon just cannot do Nitrate/Nitrite

That would work, but it would not work immediately, as carbon works through absorption. So, is there was any threat to the fish, it would likely still occur to come degree.

Also, many people don't know that carbon becomes inactive in about 2 days, and they don't remove it when they should, because it will leech the contaminants back into the water.

 

[calioutlaw1a]

Also, many people don't know that carbon becomes inactive in about 2 days, and they don't remove it when they should, because it will leech the contaminants back into the water.

What do mean?

 

[mshill90]

What do mean?

Activated carbon can only buffer water for so long before it starts leaching the contaminants back into the water.

 

[calioutlaw1a]

Activated carbon can only buffer water for so long before it starts leaching the contaminants back into the water.

But what do you mean activated carbon only remains activated for 2 days? Are you saying that it will only adsorb molecules for 2 days?

 

[mshill90]

But what do you mean activated carbon only remains activated for 2 days? Are you saying that it will only adsorb molecules for 2 days?

For the most part yes... if you do a poll, most people will tell you that they don't use carbon on the regular.

 

[charles-n-charge]

For the most part yes... if you do a poll, most people will tell you that they don't use carbon on the regular.

wow. i have carbon in my sump and i normally leave it there for like 2 weeks or so at a time. maybe thats not such a good idea

 

[calioutlaw1a]

That would work, but it would not work immediately, as carbon works through absorption. So, is there was any threat to the fish, it would likely still occur to come degree.

Also, many people don't know that carbon becomes inactive in about 2 days, and they don't remove it when they should, because it will leech the contaminants back into the water.

Carbon actually works through adsorption, not absorption, which is a very different process. Adsorption is binding of molecules (both organic and inorganic in the case of activated carbon) to the surface of the substrate. Thus, how long carbon lasts is primary dependent upon surface area (and pore size). For a given amount of carbon it can last only a few days in a poorly filtered aquarium, but will last months in a well filtered aquarium. Carbon does not leech contaminants back into the water, but rather once its binding capacity is reached it can no longer adsorb any more molecules and is no longer functional. There is minimal covalent bonding between the carbon and the molecules it binds, and adsoprtion occurs primarily through weak interactions like van der Waal's forces, ion-ion associations, dipole forces, and hydrogen bonds. Because its mainly weak bonds keeping these molecules attached to the carbon, adsorbed molecules can desorb as well and return to the water column, but this won't have a net effect on the total amount of molecules adsorbed because those that are desorbed will rapidly be replaced.

if you do a poll, most people will tell you that they don't use carbon on the regular.

I'm not sure if it's most, but it is true that many don't use carbon because it is more of an ancillary component to filtration that isn't necessary in a well-maintained aquarium. However, many people will use other forms of chemical filtration such as SeaChem Purigen, which is an adsorbant like carbon that has a different pattern of adsorption and can be regenerated unlike carbon. However, there is some overlap in the molecules that carbon and purigen adsorb, and therefore carbon can greatly extend the life of purigen between regenerations.
I personally use carbon because it is cheap, I have excessive filtration with extra room for carbon, and it is a nice extra component to filtration that mechanical, biological, and some other chemical filter media don't have the capacity to do. However, for those without the extra space I agree that its better to replace the carbon with more mechanical or biological filter media, or perhaps a different type of chemical filter media like purigen.