to run carbon or not...

strangepod

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I have heard some people say that you should run carbon 24/7 while others say that you should only do it from time to time. What does everyone on ARC think...
 
Carbon is most effective in its first 24-48 hours of use.

Some folks run it for a day or two, once a month or so, others run it all the time and change it out every 4 weeks or so. I tend to do the latter.

Choice of carbon can make a difference. Low quality carbon can contain a lot of phosphate. High quality carbon contains *some* but not enough to cause concern.

Personally I see more pros than cons to running carbon, but there are very mixed opinions out there on that.

Jenn
 
24/7

If you use Seachem matrix carbon, you'll have the best results; that stuff is by far the best carbon on the market.

And yes, you'll need to change it out every month or so.
 
Seachem states that their carbon has a longer lifespan. They suggest, during their certification training, that it lasts up to six weeks, versus other products that should be changed every 4. That isn't on their labeling as such, but it does say that a container will work in X gallons for several months.

Jenn
 
I have been using it 24/7 and it has been a great addition to the tank's filtration. I agree with the other posts... as long as you are changing it out there is not ill effect to using it. Just make sure that you buy a higher quality carbon that does not contain phosphate.

Here is a great article on carbon usage:
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I had a a po4 problem in the past and started running Seachem's Seagel (Matrix carbon and phosguard mixed) I noticed a difference in water clarity over night and a drop in po4 after a couple weeks of use. Still use it although i only run it at night because my reactor likes to put out micro bubbles.
 
There are a few major players in the production of activated carbon (AC) for both air and water filtration, such as Calgon, Norit, etc. None of the 'aquarium products companies' that I am aware of actually manufacture their own 'AC', but remarket the product under their own label. If I am mistaken in this, I apologize in advance, as I last 'researched' AC about 10 years ago.

Generally speaking, but not always, you get what you pay for. I would be very interested in reviewing the various manufacturers' test methods for how they determine efficacy/lifespan. There are 'standardized/industry acceptd tests' for adsorption capacity for both air and liquid/water applications, but not specifically for 'aquarium testing', that I am aware of. A 'quality' brand that publishes their spec's is recommended. I have had good results with the Seachem Matrix and Marineland Black Diamond brands. I had a good supply from Norit left over from R&D, that lasted me several years, so didn't need any for a while.

There are significant differences in the structure/properties of AC, depending on whether it is used for either water or air. Some less reputable brands are not very diligent in their selection/use of quality AC, designed for aquatic applications (IMO). It is common practice for manufacturers to 'wash' the ash content out of the AC after it is produced. Rinsing with acid is a common method used to accomplish this. You should ensure that the carbon has not been rinsed using 'phosphoric acid' as this will leave a phosphate residue. If you are in doubt, you may test it by putting a couple of tablespoons in a cup of RO/DI or DI water for 20-30 minutes or so, then test for phosphate.

Using carbon in an aquarium 24x7 (ie-continuously vs 'intermittently') will deplete it's 'adsorption capacity' fairly quickly. You may be assured that it is well on it's way to being colonized with bacteria within a week as well. When used, I change out carbon after 1 week to 10 days max. I don't want it to become a reservoir for nutrients and bacteria, which happens fairly quickly as mentioned. I researched AC filtration for other applications in the consumer products sector after keeping fish for many years. I was surprised, to say the least, at what I discovered.

FYI- AC filters for drinking water (like refrigerator filters) are rated for longer use due to the 'intermittent' (off & on) nature of use, plus it is being used with 'clean' (prefiltered) water. Probably TMI, but maybe it will be of benefit to someone.
 
it runs in the skimmer of the 30gal 24/7... I change it out about every 4-5 weeks..
 
ichthyoid;407661 wrote: There are a few major players in the production of activated carbon (AC) for both air and water filtration, such as Calgon, Norit, etc. None of the 'aquarium products companies' that I am aware of actually manufacture their own 'AC', but remarket the product under their own label. If I am mistaken in this, I apologize in advance, as I last 'researched' AC about 10 years ago.

Generally speaking, but not always, you get what you pay for. I would be very interested in reviewing the various manufacturers' test methods for how they determine efficacy/lifespan. There are 'standardized/industry acceptd tests' for adsorption capacity for both air and liquid/water applications, but not specifically for 'aquarium testing', that I am aware of. A 'quality' brand that publishes their spec's is recommended. I have had good results with the Seachem Matrix and Marineland Black Diamond brands. I had a good supply from Norit left over from R&D, that lasted me several years, so didn't need any for a while.

There are significant differences in the structure/properties of AC, depending on whether it is used for either water or air. Some less reputable brands are not very diligent in their selection/use of quality AC, designed for aquatic applications (IMO). It is common practice for manufacturers to 'wash' the ash content out of the AC after it is produced. Rinsing with acid is a common method used to accomplish this. You should ensure that the carbon has not been rinsed using 'phosphoric acid' as this will leave a phosphate residue. If you are in doubt, you may test it by putting a couple of tablespoons in a cup of RO/DI or DI water for 20-30 minutes or so, then test for phosphate.

Using carbon in an aquarium 24x7 (ie-continuously vs 'intermittently') will deplete it's 'adsorption capacity' fairly quickly. You may be assured that it is well on it's way to being colonized with bacteria within a week as well. When used, I change out carbon after 1 week to 10 days max. I don't want it to become a reservoir for nutrients and bacteria, which happens fairly quickly as mentioned. I researched AC filtration for other applications in the consumer products sector after keeping fish for many years. I was surprised, to say the least, at what I discovered.

FYI- AC filters for drinking water (like refrigerator filters) are rated for longer use due to the 'intermittent' (off & on) nature of use, plus it is being used with 'clean' (prefiltered) water. Probably TMI, but maybe it will be of benefit to someone.

You have just answered every question I have had about carbon/phosphate, etc. as well as shedding light as to what the problem more than likely is with my tank.Sorry to threadjack but thank you.
 
LeeS;407688 wrote: You have just answered every question I have had about carbon/phosphate, etc. as well as shedding light as to what the problem more than likel y is with my tank.Sorry to threadjack but thank you.

Thanks Lee.

I also found out that phosphate may not be the only potential problem when using AC. Sometimes during the 'activation' process, salts may be used as catalysts to lower process temperatures (really to lower costs). One of these would be FeCl2, or ferrous chloride. As many of us know iron is required for/promotes algae growth. So it goes to reason that if you have a sudden algae bloom after using a new carbon, you may want to test for iron as well, if you find that phosphate is negative.:unsure:
 
Oops. FeCl2 should read Fe2O3 (ferric oxide), which promotes algae growth.:blush:
 
dawgdude;407725 wrote: What would be the difference of the form of the ferric oxide and the GFO we already put in our tanks to remove PO4?

That's the $64k dollar question. My compliments for picking up on this.

I would guess size and degree of 'hydration'/molecular structure. The Iron oxide in AC would be very small, highly dispersed and , therefore I would venture to guess, more 'available'/hydrated. The GFO (granular ferric oxide) used for phosphate precipitation is composed of granules, with specific crystalline structures/surface area, designed to maximize the affinity for phosphate. The chemistry of inorganic salts can be very complex.

I am copying a link to an article by Randy Holmes-Farley which goes into some detail on this subject. He is a chemist with much training and experience in inorganic chemistry. Even so, he clearly avoids the exact reasons and conformations of the GFO material used to prcipitate phosphate in aquaria. Below is a quote from the article.

"How crystalline the different commercial products are is unknown to me, although one manufacturer's representative confided in me the belief that the relative crystallinity is an important difference between some of them."

a>
 
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