Carbon Desorbtion

[ge0]

I was talking to an engineer at work today about Chemi-pure elite. I was asking him how they get activated carbon to remove phosphates. He wasnt sure. But he did ask if I ever noticed desorbtion with carbon products.

 

Desorbtion is what happens when spent carbon starts to release chemicals it has absorbed.

 

So, my question is, with the small amount of activated carbon (chemi-pure and other products) in my tank, do I really have to worry about desorbtion? I know I change to chemi-pure out every 3 months or so. But, if I didnt change it out, would it release chemicals back inot my tank at concentrations high enough to cause a problem?

[tinyreef]

desorbtion is supposed to be a significant issue with carbon. many users recommend very short stints of use between changes to maintain adsorption properties. i've heard anywhere between a few days to two weeks as the popular recommended ranges of adsorption effectiveness.

 

when i'm not being lazy and regular on my maintenance i adhere to the two week suggestion.

 

as for the other 50-weeks of the year i tend to change it on an annual basis.

 

as for po4 bonding, i think it actually bonds with the carbon(?). so desorbtion of po4 is considered a potential issue of carbon use without regular replacement.

 

also, i know there used to be issues of po4 "tainting" some carbons from their origin/manufacturing process. i've forgotten the reasons behind it though but i belive most (if not all) hobby carbon out there now have eliminated that issue though.

 

all that said, carbon is still the most effective chemical filtration (imo) that's needed for certain coral setups, specifically soft corals setups with noxious corals. hth

[chrisdamage]

I change mine about once a month... its a really high quality carbon though so I can get away with it... Once every three months(even though I think this is what they reccomend on the packaging) isn't enough.

[ezcompany]

chemipure elite has gfo in the mix for phosphate removal.

i change my carbon pouch every month. mainly cuz

 

a. price

b. laziness

[Reeferton]

I would think most any kind of filter will do that to some extent. Once the media reaches a point of 100% saturation, it cannot filter any more and can drop particles back out.

Once I was spray painting this huge sculpture and the filters in my respirator got to the point of saturation to where I was sucking in fumes constantly. I think I lost some brain cells on that one.

[lil'wrasse cool]

the ready to go bag of chemi pure said good for 6 mons..? also enough in the bag for 20g but I got a 10g... so you guys say to change it a least monthly??

[tinyreef]

the chemi-pure isn't only carbon. there's some type of resin/polymer supposedly on it as well.

 

chemi-pure does work but i just find it hard to swallow that it does the miracle cures and duration it claims. in my amateur testings of it, it "lasted" longer than regular carbon but not consistently or overwhlemingly so, i.e. 3~4-weeks versus 2-weeks.

 

i'd change it out once you start noticing "bad/inferior changes" in the tank. note the timing of that and back off a week, e.g. lasted 4-weeks before bad signs of health showed, schedule the next bag for only use for 3-weeks. hth