Lets talk about Carbon

[Warnberg]

Who runs carbon all the time? If you do what do you use? Have you noticed that when you run carbon you have to dose more?

Just curious....

[Witfull]

i do, i keep appx a litre of carbon in my sump with passive flow. i use Rowacarbon. i dont dose much but i drip kalk, and a few drops of lugose monthy inbetween waterchanges. (average change 40g monthy)

[Cougra]

I only run carbon once every month or two to polish off the water. I don't believe there are any benefits of leaving the carbon in the system long term as carbon gets exhausted quickly and doesn't do much after it's exhausted. I'm not worried about the trace elements that it removes as I belive hat my regular water changes will replenish what's needed in the system.

[Warnberg]

Thanks Wit. Cougra that is exactly what my concern is, my tank seems to be doing great now, however the water is not a clear as I would have expected. I do about a 40 gallon water change every month (240 gallon tank), I have used carbon in the past and it did clear the water right up however it seemed some of my paramaters (alk, calcium, mag) seemed to diminish faster (maybe I was drinking that day...) Anyway I have thought about running carbon off and on or going to a poly filter..

Any thoughts?

[Cougra]

Personally, I would prefer using Polyfitlers in the tank then carbon. The only thing that's stopping me is the cost of the poly filter up here. I'm even toying with the idea of using some renewable resin materials such as Purigen rather then using carbon.

[Witfull]

why the dislike of carbon?

[Warnberg]

I think it removes too many of the trace elements from the water needed for proper sps growth... but that's just my opinon, I may be wrong.

[Witfull]

http://www.hallman.org/filter/gac.html

Trace elements.
Some marine aquarists worry that activated carbon depletes the aquarium of “trace elements”. While carbon has the potential to sorb certain metals considered trace elements in seawater, several factors must be considered. Activated carbon has a much greater affinity for organic compounds than metals. Foam fractioners (protein skimmers) and ozone “remove” substantial quantities of trace elements as does the metabolism of all the specimens in the aquarium. The benefits of activated carbon filtration, protein skimmers, and ozone far outweigh the possibility of trace element removal. There are many trace element additives available that replenish the “Essential elements” removed by algae, fish, and invertebrates as well as the filtration equipment necessary to maintain these specimens in captivity.

http://www.pets-warehouse.com/carbon_1.htm

“Placement of bags of activated carbon in such a way that water flows around them, but is not directly forced through them may be all that is necessary to maintain the water free of yellowing compounds” (Sprung 1995). Mr. Sprung elaborated on the “passive” approach to carbon filtering (Delbeek and Sprung 1994)

http://saltaquarium.about.com/cs/fil...a/aa061098.htm

Richard Harker's iodide absorption test results lead him to conclude that, "the use of carbon has minimal impact on iodide concentrations and that passive use of carbon has no lesser affect on iodide levels than active use."

http://www.reefs.org/library/article...htbill_wc.html

Recent works have shown that the artificial saltwater mixes on the market today contain higher trace element levels than those found in natural saltwater. Protein skimming and use of carbon are suspected to remove trace elements to some extent, but there is currently no method of measuring the level of trace elements readily available to reef aquarists. One would expect the reef animals to make use of these trace elements as well. Therefore, some method of replenishing these levels must be implemented in our reef aquariums.

Considering that artificial saltwater mix contains elevated levels of trace elements (Atkinson, data presented at WMC 1998), one can rely solely on water changes to replenish them because the initial levels from the salt mix are higher than the levels found in natural saltwater. While I do not have the actual data on hand (I'm trying to track it down at the moment), I believe that even a single 10% water change in a month can account for any loss of trace elements in the system. Many have proposed dosing trace element supplements at as little as one half to one tenth of the prescribed dosage to maintain trace element levels. In my opinion, trace element replenishment is not a major issue when considering whether or not to conduct frequent water changes. For those truly concerned, a $10-20 bottle of trace elements supplement will last you a very long time, costing even less per day than the kalkwasser.

[Warnberg]

Thank you very much Witt..... where do you get all this info?

[Cougra]

Wit:
I'm really not concerned about the removal of trace elements as I don't think carbon will remove enough to make any difference as your research states. My problem with carbon is that it has a very short active life span, nowhere near the month that people recommend leaving it in the tank for. It'll only be active for a couple days before it becomes saturated, therefore I only leave it in there for a couple days.

Polyfilter remove everything that carbon removes and more most importantly heavy metals such as copper that carbon doesn't remove. Polyfilters are more efficient in that it doesn't leach stuff back into the water once it's exhausted as carbon can. They also have a long period of absorbtion and you can see when they are exhausted so you aren't left guessing whether it should be changed or not. If there is any white material left then the polyfilter can still absorb more organic and inorganic compounds. How do you tell when carbon is exhausted?

Resins are another alternative I'm going to be testing. I like the idea of them as they are rechargable, a physically smaller amount is actually required and they are suppose to be more efficient once they absorb the compounds. They also change colour when exhausted so there isn't any guess work involved.

However, I'm not sure how the Polyfitler or the resins effect the trace elements in the tank. Then again, I think that my regular water changes will be enough to replace any trace elements that I remove with either of them before any of my animals suffer.

[Witfull]

Originally Posted by Warnberg

Thank you very much Witt..... where do you get all this info?

simple,,,its kept right next to the recipe for Bush baked beans,,,LOL

[Woodstock]

LOL~~

I use polyfilters and carbon. I use either on a random basis. A polyfilter until it turns dark (6-8 weeks) or 1.5 cups of carbon for no longer than one week. I of course soak the carbon first in ro/di water. A very small amount of carbon adsorbs a very large amount in a very short time. I like them both.

[gussy]

I have carbon all the time. Some tanks have more than others...depending on what's in the tank.

[nigle]

Oi!

"Wit:
I'm really not concerned about the removal of trace elements as I don't think carbon will remove enough to make any difference as your research states. My problem with carbon is that it has a very short active life span, nowhere near the month that people recommend leaving it in the tank for. It'll only be active for a couple days before it becomes saturated, therefore I only leave it in there for a couple days."

That is correct. The concept of leaving it in as long as a month is IMO that the build up of 'organics' 'on' the carbon once it is chemically drained is what is now a benifit. Once the carbon is no longer chemically active then the organic filter can continue for as long as you leave it in [usually a month] by which time it is so full of 'gunk' it's time to 'chemically' do the water and thus start the process over again.

Cheers!
nigle
!~!

[BoomerD]

I generally ran carbon for a week, once per month to polish the water. I have both Magnum 350 and HOT Magnum that I used for this. I prefer active carbon filtration to the passive mode of just putting a bag in a high flow area in the sump, like many people do. If you leave it in much longer than a week, it starts to become a biological filter, and will generate nitrates. Any trace elements that it removes, (and it will be only a small amount) will most likely be replenished with the next water change.