using carbon

[kevinohio]

How long do you run carbon before you replace it?

[BCreefmaker]

thats depends on many things including: Type of Carbon, your tanks Bioload/water chemistry, how often you run carbon, and how you run it (i.e. in a bag or in a phosban reactor). so there really are many different answers, all of them being, when the carbon is used up. how long that will take in your tank? no one really knows. i dont think you can really test whether it still works or not either. . im pretty shure its more of a fly by the seat of ur pants kinda thing and follow the instructions.

[kevinohio]

75 gallon tank, 1 yellow tang, niger trigger, lunar wrasse, 2 damsell,
Chemistry
Amonia 0
nitrite 0
nitrate 15
ca 420
Alk 10.6 dKh

Run in a reactor, run it all the time now.

[BCreefmaker]

what kind/brand of carbon? this is the MOST important part :P why its listed first

[Reefer07]

Is the carbon in the bio-bags fine to use that go in the little HOB filter inserts?

[Randall_James]

I run mine an average of 30 days. The best indicator is when the water starts to discolor IME. Tank water is always going to be a bit "off color" but as the carbon dies, the tint goes pretty heavy.

After adding your carbon (do rinse and soak first in RO/DI) check the color of the water every few days for a couple weeks. (a gallon or 2 in a white bucket works well) and you will see the coloration change.

If you watch this every couple weeks, you will see the color changes and can get an idea of how much carbon and how long it lasts.

[kevinohio]

Originally posted by BCreefmaker
what kind/brand of carbon? this is the MOST important part :P why its listed first

It is a fluval brand carbon, grandualted. I dont know if you need more info than this. I am new to running it.

[Aquarist007]

If you are running it in a phosban reactor like you listed above--then 4 weeks maximun.
You get a little longer because the entire medium is being used in a reactor rather then in a bag where the water really just passes over and around the outside layer of carbon.

[ccmarkab]

Hi,

Three to four weeks is about the norm.

Regards,
Mark

Originally posted by kevinohio
How long do you run carbon before you replace it?

[Randall_James]

I purchase the black diamond and use media bags. (just cheaper than purchasing the prepackaged inserts) you can just drop it in the sump in an area of good flow, I run one bag (about 1/4 pound) per 50G of capacity

[Eagles]

I usually change mine about every 3 weeks

[Randall_James]

To Reef Central
Eagles


Some reading (carbon is last on list)

[drinkhomebrew]

Is there a risk of the carbon pulling too much out? Trace elements and what not. Also I remember hearing some where that if you want to long to change it the carbon will start to leech out the toxins it removed. Any truth to that?

[Aquarist007]

Originally posted by drinkhomebrew
Is there a risk of the carbon pulling too much out? Trace elements and what not. Also I remember hearing some where that if you want to long to change it the carbon will start to leech out the toxins it removed. Any truth to that?

that is why it is suggested three weeks--that's a conservative time for changing.

[Aquarist007]

drinkhomebrew---here is how I run it--very simple to run and maintain. I can also judge when the carbon needs changied if sooner then three weeks by the flow rate out of the reactor.
The benifits of running it in a reactor is that the water is forced through the medium rather then finding its way around the sides of it--thus using more of the medium effectively.

[Randall_James]

Read the link I posted, carbon will not remove beneficial trace elements, nor will it release toxins back into the water. It simply quits working

[wolf pup]

Capn,

How do you judge replacement time by flow rate? I'm running the same sort of set up and have just stuck with a 4 week rule not really knowing if that was too short or too long. I would love a more accurate method.

[Randall_James]

Originally posted by wolf pup
Capn,

How do you judge replacement time by flow rate? I'm running the same sort of set up and have just stuck with a 4 week rule not really knowing if that was too short or too long. I would love a more accurate method.

There is a single titration test for carbon. It takes a sample of the carbon and checks to see if it is still working or not. Salifert I think is the only one that has this.

Other than that, there is no way to know if it is working or not other than to watch the water for discoloration out of the norm.

The question to "how long does it last" is impossible to quantify unless you can answer "how much gunk is in the water" Carbon has a finite ability to adsorb gunk, (it holds X amount, period)

[wolf pup]

Thanks Randall,

I think you have cleared up alot of my (and others) misconceptions.

Thank you!

[Aquarist007]

Originally posted by wolf pup
Capn,

How do you judge replacement time by flow rate? I'm running the same sort of set up and have just stuck with a 4 week rule not really knowing if that was too short or too long. I would love a more accurate method.

mine judgement is not a scientific as Randal's I have found a few times that the flow rate (return) will diminish if the carbon starts getting "gummed " up---but I still replace after 3 weeks--when run in the reactor--you know you have had full utilization of the carbon----and it is not that expensive to replace.

[crumbletop]

A friend of mine who is a chem e did a literature review on carbon and his recommendation is to change it every 2 weeks because the published adsorption curves for activated carbon in water show they pretty much saturate in that time frame (most is adsorption takes place during the first week). Here is a thread where he talks about some other important properties to consider re carbon, and factors important depending on whether you run it in a packed bed scenario (filter bag) or a fluidized bed (phosban reactor).

http://www.reefcentral.com/forums/sh...hreadid=528742

[Aquarist007]

great link---thanks--crumbletop

I always run the return of my reactor through my filter sock--which is right beside it--until the water clears
I am in effect accomplishing the same thing as washing the carbon first ?

[scrapman]

Originally posted by Randall_James
Read the link I posted, carbon will not remove beneficial trace elements, nor will it release toxins back into the water. It simply quits working

I have not yet read your link... but I think you are right.... my experience with my 90 gal tells me that a monthly change is perfect..... never had any problem/variations with my params....

[Eagles]

Originally posted by Randall_James

To Reef Central
Eagles

Thanks alot Randall_James, and nice link crumbletop

[Randall_James]

Originally posted by capn_hylinur
mine judgement is not a scientific as Randal's I have found a few times that the flow rate (return) will diminish if the carbon starts getting "gummed " up---but I still replace after 3 weeks--when run in the reactor--you know you have had full utilization of the carbon----and it is not that expensive to replace.

What you are monitoring is the "Physical" filtration of the media and this is a bit of a mistake. The filtration we are interested in is "chemical".

The physical filtration is an added benefit of carbon, even my "gravity" feed system picks up a ton of detritus.

However, I think your method at least sets a time line or a flag so to speak when to change the carbon.

I like the idea of the reactor but you must still rinse the carbon and you also need to make sure it is "firmly" packed so that there is no peculation of the media.

The 2 to 3 week active time sounds pretty good to me. Figure the coloration I watched for begins to show at 30 days (does not happen instantly)

Good link most carbon makers have taken a listen to us "end users" and leach the phosphates out for us. This has happened in the last 2 years