# Is Activated Carbon good or not??



## Wildtype Devil (Sep 23, 2011)

Hi all,

I'm quite new here and maintain low tech planted tanks with angelfish in them. I'm quite confused, whether Activated Carbon/Charcoal is good for planted tanks or not as it might adsorb necessary nutrients from the substrate as well. 

Also i tried placing about 3 tbsp Powdered Activated Carbon(PAC) in my power-head filter of a 70 gallon tank. but it all accidentally leaked and clouded my entire tank in dense black cloud which eventually subsided. I'm worried whether it will adversely affect my tank's ecology resulting problems in my fish/plants/substrate/ water column etc.

Please help, i know you can....


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## HeyPK (Jan 23, 2004)

Activated carbon is usually not needed in a planted tank. The only time it might be useful is when treating new water from the tap that contains unwanted heavy metals, such as too much copper. It will absorb needed micronutrients from the water, so you should never use it unless you know there is something in the water that needs to be taken out. The spill you had is probably not dangerous, as it has probably adsorbed everything it can hold and is no longer capable of further absorption.


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## Newt (Apr 1, 2004)

+1 for HeyPK

Also, most if not all carbons contain phosphate, even the ones that claim are phosphae free. The PO4 is released in abundance to your water column.


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## Wildtype Devil (Sep 23, 2011)

HeyPK said:


> Activated carbon is usually not needed in a planted tank. The only time it might be useful is when treating new water from the tap that contains unwanted heavy metals, such as too much copper. It will absorb needed micronutrients from the water, so you should never use it unless you know there is something in the water that needs to be taken out. The spill you had is probably not dangerous, as it has probably adsorbed everything it can hold and is no longer capable of further absorption.


okay, i'll keep this in mind... thanks for the reply....

i found everything quite ok with the tank.. but some of the leaves of amazon sword were covered with particles of carbon. maybe the carbon tried to adsorb somehing off the leaves and stuck there...... maybe it'll not burn the leaves or something like that...

does the charcoal provides vital carbon required by the plants? I was trying to put carbon in the power-head for same reason and it spilled...

Actually i'm quite new to the hobby and don't exactly understand the chemistry involved. forgive if something is way off the track or simply stupid....


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## Wildtype Devil (Sep 23, 2011)

Newt said:


> +1 for HeyPK
> 
> Also, most if not all carbons contain phosphate, even the ones that claim are phosphae free. The PO4 is released in abundance to your water column.


And i thought it'll eat away the excess phosphates and clear up some minor algae!!!! crazy me.....:crazy:

Well thanks Newt..........


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## ddavila06 (Jan 31, 2009)

Wildtype Devil said:


> And i thought it'll eat away the excess phosphates and clear up some minor algae!!!! crazy me.....:crazy:
> 
> Well thanks Newt..........


we all learned something out of your post! 
i am already NOT doing carbon so im good. instead i havea few baggies with peat moss. i also have some lava rock (which i was told it makes for a great place for bacteria to grow in) and the ceramic rings things..


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## aquabillpers (Apr 13, 2006)

Walstad-type tanks rarely if ever need anything added other than food for the fish. That is the beauty of them.

Activated charcoal can be beneficial in fish-only tanks, but is rarely needed in planted tanks. In fact, it might remove some nutrients from the water column.

Good luck!

Bill


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## Zapins (Jul 28, 2004)

Newt said:


> Also, most if not all carbons contain phosphate, even the ones that claim are phosphae free. The PO4 is released in abundance to your water column.


That must be why people use it to enrich soil... I had often wondered what it was contributing. Very interesting. Any idea how much PO4 it releases, is the amount enough to measure with our 0-10 ppm kits accurately?


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## Wildtype Devil (Sep 23, 2011)

ddavila06 said:


> we all learned something out of your post!
> i am already NOT doing carbon so im good. instead i havea few baggies with peat moss. i also have some lava rock (which i was told it makes for a great place for bacteria to grow in) and the ceramic rings things..


Well yeah i'm learning a lot from this one....

all of my fish are doing fine and plants seem to be ok, so i guess, I'll let this tank run as an experiment instead of doing the w/c i planned for today...

what i observed is that almost all of the algae on glass surface, leaves and driftwood is covered with a thin film of carbon as it tied to adsorb the organics and stuck over there..... This gives me a bit of optimism... maybe the carbon provides excess phospates (we cant control them anyway!) but cuts back on other essential nutrients which algae require... such as iron... just ahope... only time will tell.....

Whatever be the case, I won't dose my tank with carbon again unless critically required.... you never know what tips th balance in favor of algae instead of plants...... I wont play with the tank's ecology.....

My biggest concern as yet was fish getting irritated & carbon damaging the leaves of plant... that seems ok..... as far as nuitrients go, i feed plenty of fishfood, let the organics accumalate, so i guess, with time they shall revert back to optimum levels as carbon's adsorption capacity dicreases overtime...

what ever be it, thanks guy for steering me through.... insights one and all are always welcome and sincerely regarded........

Thx and regards,
Shivam
India


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## dstrong (Feb 13, 2011)

Zapins said:


> That must be why people use it to enrich soil...


I don't know about the PO4 but it is used in soil as a sort of nutrient lock. It abosorbs as much nutrients as it can to keep it in the soil and not the water column then slowly releases it for the plants roots.


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## Newt (Apr 1, 2004)

Zapins said:


> That must be why people use it to enrich soil... I had often wondered what it was contributing. Very interesting. Any idea how much PO4 it releases, is the amount enough to measure with our 0-10 ppm kits accurately?


I found this out quite awhile ago with my 20 tall that was lightly planted. I was using a HOT Magnum with the Aquarium Pharm Research Grade. It would peg my Hach test kit which went to 50ppm.
Yes FIFTY ppm


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## niko (Jan 28, 2004)

I've seen this only once, but the carbon was definitely a culprit - it released a bunch of waste all of a sudden. I'd heard of that but never really believed it. Carbon is basically a piece of material penetrated by a maze of tiny channels. The particles get trapped in them. Physical, mechanical, and chemical forces attract and keep the particles stuck in the channels.










Why would the particles suddenly decide to leave the channels? 
I've seen it happen. Since then I do not think of carbon as a safe 'storage' for nutrients.

--Nikolay


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## HeyPK (Jan 23, 2004)

Activated carbon has a great deal of surface area and is capable of adsorbing various ions. The manufacturing process that produces activated carbon should produce a product that is capable of uptake rather than exchange of ions. In cases where a lot of phosphate was released, the activated carbon must have been loaded up with phosphate previously.


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## Newt (Apr 1, 2004)

It depends on what the carbon is made from. Remember its all from organic material i.e. wood, coal, peat, etc. Its there to begin with.


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## ddavila06 (Jan 31, 2009)

dstrong said:


> I don't know about the PO4 but it is used in soil as a sort of nutrient lock. It abosorbs as much nutrients as it can to keep it in the soil and not the water column then slowly releases it for the plants roots.


good point, i know someday i will set up another tank from scratch! i will remember that


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## HeyPK (Jan 23, 2004)

Wikipedia said:


> Activated carbon is carbon produced from carbonaceous source materials like nutshells, peat, wood, coir, lignite, coal and petroleum pitch. It can be produced by one of the following processes:
> 
> Physical reactivation: The precursor is developed into activated carbons using gases. This is generally done by using one or a combination of the following processes:
> Carbonization: Material with carbon content is pyrolyzed at temperatures in the range 600-900 °C, in absence of oxygen (usually in inert atmosphere with gases like argon or nitrogen)
> ...


The above may indicate why some activated carbon has a lot of phosphate. However, from reading more of the Wkipedia information on activated carbon, I get the impression that most of it is made to have a lot of absorption capacity, rather than to deliver something it has been loaded with.


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## niko (Jan 28, 2004)

In my case I overdosed the tank with P severely. The brand new carbon was exposed to this P for a week. I started changing about 40% of the water every two days to reduce the P. I managed to reduce the P in about 2 weeks. Then a day later I had a huge P spike again. It must have come from the carbon absorbing and releasing P. Removed all carbon, changed water again for a few days. P did decrease. Even if my test kits were useless as they usually are for precise numbers I did catch the trend.

Bottom line - another reason why it's stupid to load your water with nutrients. Besides Activated Carbon there are other "things" in the aquarium that can suck/release nutrients depending on what happens in the tank. Organics (that the US hobby is very much oblivious to) are a good example. 

All that is another good argument against EI or PPS which load the water with nutrients in an expectation for the amazing plant growth to magically kill all algae. Once again -they work till the day when trouble starts. Then the answer is more of the same - water changes/nutrient increase/decrease.

Food for thought: ADA uses carbon in the first few weeks of the tank development only. After that they do not use carbon. Not a bad idea to understand and know why they don't use it as a slow release storage for nutrients.

--Nikolay


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## HeyPK (Jan 23, 2004)

Niko, What were the problems you had with phosphate being too high?


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## Wildtype Devil (Sep 23, 2011)

I came across a page on http://www.hallman.org/filter/carbon.html while searching more about activated carbon. here are the excerpts.

hope it provides some good info....:idea:

I asked Leo Morin, chemist for the aquarium products company Seachem, some questions about the use of activated carbon, and here is his response:
Date: 12/28/95 06:14:31 AM
From: Leo Morin ([email protected])
Subject: Re: Phosphate leaching of activated carbon.
To: Bruce Hallman ([email protected])

Bruce,
[In response to your questions...]

BH> Is the use of activated carbon in aquarium filtration worth the risk?

I think the benefits far outweigh the risks, particularly in non-reef aquaria. Even in a reef aquarium, it is possible to use carbon and minimize the risk by selecting the right carbon and pre-soaking it in DI water for several days to leach out the majority of the leachable phosphate.

BH> Do we need to worry about buying activated carbon which has been washed with phosphoric acid?

That question is based on the common misconception that phosphate in carbon arises from acid washing with phosphoric acid. I know of no major carbon today that is acid-washed in phosphoric acid. Acid-washed carbons are preferable because they contain less, not more, leachables such as phosphate. Acid washing is usually done with hydrochloric or sulfuric acids, not phosphoric acid. The phosphate in carbon arises from the organic or "once living" source of all carbons. All such materials will be rich in phosphate because all living matter is rich in phosphate. DNA, RNA, energy transfer molecules, and a host of other important biological compounds are phosphates.

BH> Do the "premium" activated carbons leach less phosphate as a rule than the "budget" activated carbons?

That is not a blanket rule. Acid-washed carbons leach less phosphate than others and these are usually more expensive. Coconut carbon leaches less than coal based carbons, but that is because coconut carbon is microporous and has a slow rate of adsorbtion as well as leaching in water, since it is enginered mainly for gas filtration rather than water filtration.

BH> Should I buy "brand name" activated carbon, or is "generic/bulk" OK?

Again, that is hard to answer. What is important is identifying a good carbon. Brand or generic doesn't really matter.

BH> How much should I use? How often should I change it?

I prefer to use little and change it frequently rather than more and changing it infrequently. I recommend around 100 mL for each 20-40 gallons and changing it at least once a month or sooner.

BH> An "expert" told me that I should use coconut shell carbon in my filter because that's the best. Is that good advice?

That "expert" wasn't very expert. Coconut carbons are microporous and are excellent for gas filtration, but do poorly with water filtration. Water filtration, particularly aquarium filtration, requires a macroporous carbon. The easiest way to judge that is the carbon density. The lighter weight the carbon is for a given volume the better. You will find that coconut carbons are comparatively dense.

BH> But how can I practically choose a "good" activated carbon? A package of carbon costs typically less than $10, but a phosphate test kit costs more than $20!

I agree that personal testing of carbons can get a bit expensive and time consuming.

Phosphate leaching is one parameter for carbon evaluation, but is not the most important. Since most aquarium carbon suppliers do not give specifications for their carbon, selection usually requires some detective work. Our (Seachem) carbon gives all important specifications on the label. I would suggest the following guidelines:

1) If the labels gives key specifications (porosity, density, ash and phosphate content) then the supplier likely has nothing to hide and the carbon is likely a good one.

2) If the carbon boasts no phosphate, then the supplier is either lying or doesn't know any better. Neither is very reassuring.

3) Compare weight and volume. The less weight for a given volume, the greater the porosity and the better the carbon, all else being equal. You can usually do this without buying the product first. After buying the product, this parameter will be reflected by the carbon's ability to float and fizz.

4) In terms of porosity suitable for aquarium filtration, coal based carbons are best, followed by wood based. Coconut or other nut shell based carbons are least suitable. This information may be availble on the label.

5) In terms of ash and phosphate content, acid washed carbons are better than non-washed carbons. Acid washed carbons have had much of their ash and phosphate washed out. Ash is important because it is responsible for "pH shock". Some carbons can increase pH to over 10 in a very short time. An acid washed carbon will barely increase pH to 7 over several days. Carbons that do not alter pH are usually the same carbons that will not leach much phosphate. Ash content may be available on the label, but sometimes it is unreliable. The store owner may be familiar with what the carbon does to pH.

6) Soaking in DI water and testing for phosphate is impractical, but may be necessary if phopshate is considered an important parameter. In my view, it is important only for reef aquaria.

7) Some physical characteristics that should be evident before buying should be considered. Particle size should be about pin-head. Powdered carbons offer no real advantage and are difficult to handle. Large particle sizes become impenetrable by water and so only the outer 1-2 mm of the particles are adsorbent, making as little as 20% of the carbon useful. Spherical shape is ideal hydrodynamically for unimpeded water flow and inability to pack, and is therefore superior to random granular shapes. To my knowledge, the only spherical carbon available is sold by Seachem.

I hope this helps.

Leo

BH> Yes it does, a million thanks!


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## niko (Jan 28, 2004)

PK



HeyPK said:


> Niko, What were the problems you had with phosphate being too high?


In the tank that I described there was only Hygro polysmerma and a huge arrowana. The plant loved the high P. The arowana could care less. P was about 30 ppm according to the cheapo test (that everyone loves to use anyway)

In other tanks I had foolishly raised the P to above 40ppm. How much above I do not know. Could have been 80. I've told that story a few times too. I had about 60 species of plants total. All of them just stunned. Or rather - stopped growing. There was no new growth. No plant ever died, but they never produced new leaves. Only plant that grew was Java Moss and it grew pretty slow. Hygro polysperma produced leaves that were very beautiful - tender salmon pink (like H. ovalis). But it also stopped growing at some point.

Wildtype,

This is very good practical information! Thank you for it!

But in this hobby there is one basic fact. I hope it changes some day:

99% of the products are crap. 
We use them because of ignorance + lack of something better.

No manufacturer is in this business to help the planted tank folk. Or the non-planted freshwater aquarists either. Period. It's amazing how little the manufacturers know about a planted tank. This is evident from the stupid products they offer. Advanced saltwater seems to be a very different game. So no matter how much we discuss something the bottom line is - if you want quality and guarantee you need to be getting chemicals from a chemical supply store, lights from a non-aquarium supply stores, and so on.

--Nikolay


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## Wildtype Devil (Sep 23, 2011)

Well.... carbons sucks out everything.... is there something that sucks out the carbon from the tank??


every thing else is ok..... but somebody plz help me remove the carbon off the leaves and the walls....
no matter how much I try scrubing it off, it still lands up there....


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## Newt (Apr 1, 2004)

Its probably Rhodophyta (sp?) 2 algae and not carbon.


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## londonloco (Sep 25, 2005)

This is a very interesting thread. Over the years I've often heard that carbon will release back into the water column, but I've never read any proof, only the statement. I've stopped using it completely, even in my reef tank. Just seemed like another unnecessary.


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## Wildtype Devil (Sep 23, 2011)

Sorry guys,
I had been away for a while....

I performed a water change and cleaned the tank. Now it's much better although some of the leaves could not be cleaned but I hope eventually they'll be replaced with fresh leaves....

Also this time i had few clicks for you to figure out what it is...... (uploading pics for the first time, its a twisted tale, hope I make it through... )

Here they are... the tank before cleanup...





































hope now you may be better to analyze whether it's an algae or just carbon.. (it was slimy to scrub off and had a very "Not an Algae" feel to it... 

Btw here's my tank after clean up.... (not the best but free from disaster  )

The left Side:









The Right Side:









the full shot:


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