Activated Carbon myths.

[PowermanKW]

I hear a lot of conflicting infor on GAC. Just curious about a couple.

Lateral Line Disease....true or false? I hear that GAC can cause LLD if not wash or if fines get away. What is the deal with that? How much are we talking about.

If you leave GAC in too long it poisons the tank??? Personally I don't get it. it would only realese what it adsorbed which was in the tank to begin with.

Does GAC release what it absorbed or not?

Can GAC be rinsed off and used again. Can it be reactivated? Some take it out and rinse it and use it some more. My ROX definitely gets clogged with detrius and I have tried to wash it and use it longer but seems like a pain. Just curious.

And the ever popular..... GAC takes out trace elements. what is the truth behind this? Any?

[bertoni]

I don't know of any reason to believe that GAC can cause disease or create problems with trace elements. Lots of people run it all the time to bind organic molecules, which is its function in our systems.

GAC will become a biological filter over time, functioning much as bio-balls and similar media, which could be a problem with some tanks. It should be replaced monthly or so. Some people rinse it once a week or so to prolong the life, but I've never bothered. That process might help, though, if the carbon is rinsed in fresh water, since it'd tend to kill microbes and remove detritus. I suppose if carbon were left in the system long enough, it might release what it's captured back into the tank, but likely only after the compounds have been through a bacteria or the like. :) That's not likely with any moderately reasonable replacement schedule.

Carbon can be reactivated in ovens designed for the process, but they operate at far higher temperatures than we can produce at home.

[Randy Holmes-Farley]

And the ever popular..... GAC takes out trace elements. what is the truth behind this? Any?

GAC binds organics well, and some trace elements (copper, iron, etc) are mostly if not completely bound to organics. So yes, GAC may cause some trace elements to be lost (whether that is good or bad may depend on your point of view on whether these are overabundent in the tank, or deficient). How significant this is isn't known. I don't recommend adding any more trace elements just because you use GAC, however.

[SeasonedReefer]

I have heard from a LFS owner that GAC also releases phosphates. He was told this by someone at Marineland the makers of black diamond.

[Jared J]

Read this please:

http://joejaworski.wordpress.com/2008/05/09/does-a-reef-tank-need-carbon/

[scolley]

Wow! Great article. Thanks for posting that!

[danrobberg]

yea, excellent article

[Mako]

Hmmm....it was a good read, but didnt he get it wrong on the iodine numbers below 600 being an indicator of quality activated carbon. I believe it's actually the opposite.

[plankton]

Great article.

I leave GAC in ro/di overnight to hopefully leach out phosphates then test the water for phosphates then rinse again with ro/di water before using in tank. If you measure phosphates in the overnight rinse water then consider using another brand of GAC.

Scott

[spleify]

Interesting article, that was definitely a good read. Thansk for posting that.

[PowermanKW]

Thanks guys. Anyone else heard it causes LLD? Never knew where that came from.

[THEUNION1]

That was great reading thank you!

[Randy Holmes-Farley]

I leave GAC in ro/di overnight to hopefully leach out phosphates then test the water for phosphates then rinse again with ro/di water before using in tank. If you measure phosphates in the overnight rinse water then consider using another brand of GAC.

In most cases, there is very little phosphate coming from good aquarium GAC. Yes, it can look like a lot in a small amount of water, but if you scale that up to aquarium volume, by dilution, the concentration looks very small. In general, I do not think that phosphate is worth worrying about wth respect to good quality aquarium GAC. :)

[wah-zoh]

great info!!! i have learned more from this site in 1 week than i have with trial and error for 1 year.

[tmz]

Nice article.The chart and rankings of various products,however, does not jibe with other available information and seems to be of dubious value.

[Boomer]

Jared

Nice piece I must say and well thought (but has some errors ):thumbsup:

Just three things to add that stand out as larger errors.

1. Iodine # less than 600

That is not so, you can have Iodine as high as 1,000 and still have very superior properties if it also as a high Molasses and MB numbers. For example, the Warner and TLF GAC both have Iodine # of over 600. ROX has a I# of over 1,000 and no GAC in this hobby can out compete it adsorption wise. And I disagree 100 % with his placement of SeaChem in the good an not the Excellent where it belongs. Adsroption dye test show and support this. I also disagree with ROWA in the excellent = Good and Chemi-Pure in Excellent = Good.

2. "Acid " washing. I do not want anybody getting confused on acid washing. Acid washing is not washing with phosphoric acid but Nitric or HCl and is what you want. The phosphoric acid is used in Chemically Activated GAC, and in some cased here Acid Washing again is with HCL or Nitric acid after the Chemcial Actiavtion with Phosphoric Acid.

3. Pellet carbons are VPC (par, Elos and ROX , which are LPC) and not LPC GAC and to large a grain size.Yes, they still work but are not very efficient.

[Boomer]

Anyone else heard it causes LLD?

Yes, I have herad of it but do not believe in it. LLD is almost always a nutritional issue or from heavy metals plugging up the neuromasts

[becact]

Jared

Nice piece I must say and well thought (but has some errors ):thumbsup:

Just three things to add that stand out as larger errors.

1. Iodine # less than 600

That is not so, you can have Iodine as high as 1,000 and still have very superior properties if it also as a high Molasses and MB numbers. For example, the Warner and TLF GAC both have Iodine # of over 600. ROX has a I# of over 1,000 and no GAC in this hobby can out compete it adsorption wise. And I disagree 100 % with his placement of SeaChem in the good an not the Excellent where it belongs. Adsroption dye test show and support this. I also disagree with ROWA in the excellent = Good and Chemi-Pure in Excellent = Good.

2. "Acid " washing. I do not want anybody getting confused on acid washing. Acid washing is not washing with phosphoric acid but Nitric or HCl and is what you want. The phosphoric acid is used in Chemically Activated GAC, and in some cased here Acid Washing again is with HCL or Nitric acid after the Chemcial Actiavtion with Phosphoric Acid.

3. Pellet carbons are VPC (par, Elos and ROX , which are LPC) and not LPC GAC and to large a grain size.Yes, they still work but are not very efficient.

Boomer, can you expound upon what VPC and LPC stand for? If I had to guess, I would guess Vapor Processed and Liquid Processed... Is the only reason pellet carbons do not work well because of their grain size, or does the different processing have something to do with it? I'd like to explain to my friend why Brightwell carbon is not that good, which I've heard here before.

Also, what is your opinion on Marineland's Black diamond product?

[Boomer]

Becat

VPC = Vapor Phase Carbon

LPC = Liquid Phase Carbon

Is the only reason pellet carbons do not work well because of their grain size,

In general yes. VP operation requires larger grains due to the larger flow restrictions smaller grains have for vapor /air. Air flows though larger grains much more easier than smaller ones and vapor /air has better diffusion rates and there is less channeling of the air, which is a function of Break Though Flow Point. Water/liquid is just the opposite so to speak due, partly due to its mass where the smaller the better it is. And since the grains are smaller the bulk vol of GAC is more. Meaning, you can stick more golf balls in a 5 gal bucket than you can stick baseballs, an analogy of granular GAC to Pellet GAC Water also has a higher BTFP.

Black Diamond is fine to use and the rating Joe gave it sits fine with me. GAC is kind'a a choice, where one can always use more of the cheaper or poor grade than a expensive grade that adsorbs more. Another issue for some is that do not want some GAC sucking all out of their tank to quickly or that just want some adsorption and not say great adsorption so they use a pellet GAC or large grain granular GAC. Me, I'm into quality and
efficiency. I am trying to remove as much as can, which is the reason for GAC. Look at it this way do you want a cheap crappy skimmer or a nice efficient more pricey skimmer ? Well, the same for GAC. People in this hobby seem to make a lot of hope-de-lah about skimmers and do not seem to realizes that no skimmer can out compete GAC... period. The only issue with the GAC is it costs more in the long run vs a skimmer. Meaning, if one could regen their carbon there would be zero use for skimmers.

[becact]

Thanks! So basically VPC (ie-pellet) has the same absorption properties, but less surface area to do it with, which is why it is less effective volume to volume with a granular GAC?

Is all pellet form carbon in fact VPC?

I didn't know carbon, in large quantities I'm guessing, could perform the function of a skimmer. That is really cool. Someone should start up a company making carbon filters for home aquariua with a mail in service that would recharge users' carbon for a fee.

[Boomer]

So basically VPC (ie-pellet) has the same absorption properties, but less surface area to do it with, which is why it is less effective volume to volume with a granular GAC?

Yes, basically but some of it is processed for VPC. All GAC is not processed the same and some GAC adsorb certain things better than another GAC. Some VPC also have smaller pores for gases than LPC and those small pores plug up fast in water when dealing with large molecules. Lignite is best for water, Bitum is good for water or air depending and Coconut is best for VPC.

Is all pellet form carbon in fact VPC?

In this hobby all, except Elos ( water/air) and ROX ( water) which are very small pellets and ROX is really small like mechanical pencil lead. This is also includes SeaChem Matrix more or less a ball shaped pellet which is LPC.

[bertoni]

It'd be nice to have a good article on carbon available... :)

[PowermanKW]

Thanks guys for all the great info and questions. I use ROX right now, but it is so tiny, its kind of a pain. Two weeks and it is totally plugged.

[becact]

Thanks guys for all the great info and questions. I use ROX right now, but it is so tiny, its kind of a pain. Two weeks and it is totally plugged.

You should try kneading the carbon daily. You can also rinse it off every once in a while.

[tmz]

Thanks guys for all the great info and questions. I use ROX right now, but it is so tiny, its kind of a pain. Two weeks and it is totally plugged.

Are you using it in a reactor, canister, bag in th sump?

[DeepReefExotics]

So basically the ROX carbon is one of the best avail? I currently have hydrocarbon and ROX and wanted to know which one i should buy to refill my filter next.

[Boomer]

No, ROX is the best :) However, Hydrocarbon is in second place and I see no real need to replace it.