Carbon In Aquarium Filters

[Iron Man]

Besides carbon seeping chems it had absorbed back into the water column after a while being in the filter, is there something harmful about it?

I find it odd that it seems a majority of the fresh water crowd don't like it yet the majority of the saltwater crowd bless its holy name. LOL

The saltwater crowd is all about those trace elements/electrolytes, etc being in perfect balance in their water so if carbon was absorbing so much valuable mineral content I would think they'd be cursing carbon instead of blessing it.

I'm just wondering because I have heard a few in the freshwater crowd say that it absorbs trace elements (minerals?) out of the out that the fish need. If this was so wouldn't it lower the ph of the water, etc.?

I'm kinda confused on the "dangers" of carbon and how it got its bad name in the freshwater crowd (besides leaving it in too long).

 

[Bignose]

First and probably foremost, carbon got a bad name in freshwater because it is completely unnecessary. It is just another thing the filter manufacturers want you to buy and buy a lot of because it needs replacing. But, it doesn't do anything for a healthy well-maintained tank, so you are just wasting your money.

Secondly, carbon absorbs dissolved organic chemicals (DOCs). DOCs, tannins being a very good example, actually perform some useful functions in an aquarium. Most significantly, DOCs help bind up heavy metals and make the heavy metals so that they aren't anywhere nearly as dangerous for the fish as they otherwise might be. Also, these bound-up metals are in a form that are much, much easier for plants to take up and get their necessary micronutrients from. But, if carbon takes out these DOCs, you don't get the safety from toxic metals and plants can't get their micronutrients as easily, so carbon can ruin some of the natural processes that are going on.

Carbon won't take out any significant number of minerals -- carbon absorbs organic molecules preferentially, not inorganic metals or minerals. Carbon will take up some, but it will be a very small number.

So, in summary, carbon takes out the useful DOCs and doesn't perform any useful function, so why waste money on it? That's why it has a "bad name" in freshwater.

 

[shang hi]

i find carbon usefull, it helps keep tannins out of my water. some dont like it because it can get expencive...

 

[Iron Man]

Well in the saltwater community they use equipment such as protein skimmers to remove organics....so I guess its more of a bad thing in saltwater than freshwater. I do know the kind of tank I'm planning (maybe rams, neons, cories, tetras) is going to prefer acidic water so I guess the more tannins the better?

So I guess you've answered my question, and I won't be using carbon. Thank you!!