Who uses activated carbon?

[Nandopsis]

I love all the big fancy words, but lets try from now on to keep it fairly simple so everone can understand what is being discussed.

There seems to be a conflict of so called facts here. Now correct me if i'am wrong...your stating that once the ADsorption capacity of the AC is filled it will start leaching all of the contaminates out at once?

If so i would like to write TFH to ask them why they are clearly stating that "Carbon doesn't suddenly discharge all of it's contaminants unless it's reactivated by being processed again at a temperature of atleast 100 degrees C, something that doesn't happen in a fish tank. (If it did, the consequences of the heat would be much more dire to the fish than the release of the contaminates!)"

[RD.]

Sorry Jay, I thought my previous comment was fairly easy to follow.

your stating that once the ADsorption capacity of the AC is filled it will start leaching all of the contaminates out at once?

No, that's not what I said. I said that there are cases where DOC's can take the place of a heavy metal molecule (for example lead) which will obviously cause more harm in a system, than good. If enough lead, copper, etc is released at once (due to carbon having an affinity for non-polar adsorbates such as organics) then your fish could be in for a world of hurt. AC does not need to be reactivated for this to take place.

The bottom line is this, in most closed systems (such as aquariums) activated carbon loses its effectiveness in a very short period of time, and leaving it in any system for prolonged periods has risks involved. While I'm not personally concerend with the risk of a build up of heavy metals in MY tap water, I know many fish keepers who are (due to their local water, house pipes, older hot water tanks, etc) and IMO generalizing about what might not happen, instead of what might, is taking a rather cavalier attitude.

Edited April 6, 2006 by RD.

[Nandopsis]

Ahhhh i see now.

Interesting thanks for clearing that up.

[Tanker]

I use it every couple of months... run a little AC Mini with a filter bag stuffed full of it on each of my tanks for a couple days... just cycle it around the fishroom untill all the tanks get 'hit' (takes about three weeks) and then clean it out and toss the black stuff.

I do this for the simple fact that the water (and hence the room) tends to get a little funky and the carbon clears the air, so to speak. Sponge filters are great little products but sometimes they need a little shot in the arm.

[skinless]

used to use it. got some HITH with my cichlids, and took it out. HITH has cleared well, so i will only use it for med removal, which would be in my QT.

ive heard that it maxes out much sooner than a month, a few weeks maybe?? thats kinda expensive. i just bought more cut to fit mech that can be rinsed and be used instead of filter cartridges. my canister just had more bio added in place of carbon. weekly water changes and things like removing any uneaten food after 5min should keep the tank clean looking.

[midgetwaiter]

With spring run off season the heavy metal concern is timely. Water treatment plants will add alum (Aluminum Sulfate) to the water in order to reduce the ammont of suspended sediment. It's not usually dangerous to fish in that concentration but it can harm inverts.

Use of a good water treatment like Prime is recommended when alum is being used in higher doses like last year's flooding. Most water treatments don't touch it.

[RD.]

The comment below was copied from a post that I made on another forum back in 2004.

Prime users may find this interesting.

I received a response today from Dr. Greg Morin of Seachem, and here's what he had to say with regards to my question about Prime no longer mentioning detoxifying heavy metals.

Prime has not changed, that is just a clerical error in the text

description during one of our website updates. it should be corrected

shortly. Thanks for bringing this to our attention. We did remove

from our labeling as it is a fairly minor effect and did not want to

mislead people into thinking it was some kind of heavy metal removing

product... but maybe removal of that has caused more confusion since

competitors still make the claim for an effect that is identical in

their products as well.

I then asked him about the chelator they used, and specifically if it was EDTA.

His response:

No. The principal that operates is the precipitation of the metal salts of the anion used for the dechlorination/reduction process. So products using sodium thiosulfate precipitate (metal)-thiosulfate, we use a hydrosulfite as one ingredient for example, so the (metal)-hydrosulfite is precipitated.

I then asked specifically which metals Prime would precipitate, and Dr. Morin's response was:

Typical heavy metals, lead, zinc, mercury, copper, etc.

Then Seachem Support got back to me, with a slightly more detailed response to the same question:

Prime does detoxify heavy metals. It use to be on the label but we

took it off because it could potentially become misleading if someone

had higher levels than allowed by the water municipality. We are

going to add it back to the website and eventually back to the label.

Just like all other water conditioners that detoxify heavy metals, it

can only do trace amounts that are allowed by water municipalities.

Best Regards,

Seachem Tech Support

Interesting ..............

Perhaps the best solution to heavy metal removal, is having a planted tank, or one that is heavy in algae/biofilm.

Biosorption. Fishkeepers have often noticed that poisoning due to heavy metals is rare in well-established planted aquaria, where plenty of humic floc incorporated in the substrate chelates them. There is a further biological component to this aspect of "chemical" filtration: heavy metal ions also adhere to the cell walls of biofilm microbes and in the gummy biofilm itself. In experimental wastewater technology, microbes are even being deliberately cultured, to "filter" heavy metals from industrial effluents, a process called "biosorption." As you see, chemical filtration can't always be separated from biofiltration.

I think the most important thing to keep in mind with water conditioners that state they will 'detoxify heavy metals, is:

"Just like all other water conditioners that detoxify heavy metals, it

can only do trace amounts that are allowed by water municipalities."

It appears what happened is Seachem decided to remove it from the label (this obviously was no oversight) due to the fact that it was slightly misleading. Prime won't exactly 'detoxify' heavy metals, what it will do is detoxify 'trace' amounts of heavy metals. Two different things altogether.

It's not like someone in NYC or DC who's lines are being fed via 100+ year old lead mains is going to be safe from lead in their tank just because they use Prime. My guess is the the new labels and the wording on their web site will carry the caveat of "will detoxify trace amounts of heavy metals".

Seachem support stated:

"we took it off because it could potentially become misleading if someone had higher levels than allowed by the water municipality."

probably meaning ....... to avoid potential law suits.

BTW - I don't believe that Seachem ever added anything back to their labels with regards to detoxifying heavy metals, and this is now 2 years later.

[Froggie]

probably meaning ....... to avoid potential law suits.

Not a wholly unreasonable position to take. It just shows that people need to be careful and have a decent understanding of their water conditions rather then blindly relaying on chemical treatment. I know that our water can fluctuate wildly, especially during spring-run off. Not the best time to do water changes when your source is a large river in an area with high concentrations of potash and widespread usage of agricultural fertilizers.

[skinless]

this thread is hellagreat. bump for votes

[Slough Shark]

What a great topic! Thanks for bumping it Skinless, I had no idea this stuff could have such a negative effect...

[Sam Chicklets]

I have worked in a water treatment plant at a chemical plant and they use it for their potable water. They only change it twice a year.

[Albertan]

One additional consideration for carbon. If you believe in the theory that fish release pheromones that can affect their growth in aquaria, whether it be young fish trying to outcompete siblings or adults in response to poor water conditions, then you might also want to consider the fact that carbon is supposed to remove these pheromones. I'm not sure where I stand on this theory. But I do know that while carbon may remove these potentially detrimental hormones if they in fact exist in aquaria, water changes will absolutely, unequivocally remove them also.

[Qattarra]

On my tanks with two filters, one of them always has fresh carbon (no older than 3 weeks). I've read many articles on the subject and believe it does help keep the water "fresher" than without. On my single filter tanks , it's sponge/floss combo.