Does Activated Carbon ACTUALLY pull out major/trace minerals?

[awokenreefboy]

Been binge watching the Beyond the Reef Podcast and Adam had on a man named Dong Zou. When the topic of activated carbon came up he mentioned a few things that I can remember off the top of my head.

1. Carbon should be changed out every 3 days - anything past that it’s pretty much useless.

2. Carbon strips a lot of minerals from your water.

My question is, are there actually any hard evidence on these things when it comes to reefing specifically? Has anyone actually tested their water to see if it does in fact pull out a significant amount of minerals?


Here’s a little bio on him so yall have some background:

“Dong has a PhD in chemistry and worked for several pharmaceutical companies in various therapeutic areas including anti-inflammatory, cancer, pain management and anti-infectious diseases. He developed his first interest in marine invertebrates when he was working as a post doc at the University of Virginia. He has been in aquarium hobby since he was in college and he got into the saltwater hobby in 2004 after setting up his first marine fish tank for a Nemo and after he discovered the Boston Reefers Society.

About 10 years ago, he cofounded his first company on drug discovery. Soon after that, he was able to combine his passion for coral and his experience in the pharmaceutical industry and cofounded a new company, eCove BioMarine. This company focused on aquaculture coral for drug discovery and bone grafting. His current company, AcroGarden Inc, was then founded to hold the intellectual properties and to study coral farming. AcroGarden is now his primary focus. The company produces aqua-cultured coral, mainly SPS, for the hobby.”

 

[anthonymckay]

I'm curious about this as well. I watched a YouTube video the other day where a guy was talking about using CAC (catalytic activated carbon) because it "doesn't remove trace elements like regular carbon". This was a coral farmer using the reef moonshiners method of dosing individual trace elements. So at face value it sounded plausible.

But... those trace elements are ionic metals. Not organics. How would carbon remove those?

 

[fish_collector]

Yes Dong Zou is a relatively well known coral farmer. If you ask 10 people about carbon you'll likely get 10 different answers. I personally don't think it's significant enough to cause anyone any concern, but I can't answer your question at the technical level that you may be looking for. But I can attest that there are many thousands of reefers who use carbon regularly for various reasons. Whether it's for water clarity, toxin/medication removal, etc it just plain works. I've read a lot on the subject of carbon and it's connection to HLLE in certain fish (think hippo tangs), it's believed that dust from lignite carbon (from coal) is a contributing factor in the disease. I have used coconut shell carbon for ages without issue. But back on topic, I'm sure if you dig deep enough, you'll find ICP results with and without carbon use.

See if you can have a moderator move this to Randy's chemistry forum, I think he'd have the answer you are looking for.

If you've got some spare time this is a pretty interesting read on the subject of carbon.
https://books.rsc.org/books/edited-...ivated-Carbon-Fundamentals-Classification-and

 

[slingfox]

Do an ICP test before running carbon and do another a few days later to check on trace element levels. CAC carbon is supposed to have the lowest impact on trace elements.

 

[Randy Holmes-Farley Verified Community Expert]

GAC both adds and removes some trace elements. Christoph at Oceamo showed this for one brand (link below). Be careful in interpretation, since the experiment was done to show the qualitative effect, not a quantitative effect, because he used vastly more GAC than a reef aquarium would use.

I personally am not overly concerned because it just gets buried into the larger sources and sinks of various trace elements in a typical reef aquarium.

I do not agree that 3 days is the limit on GAC utility in most tanks. In any case, tanks do not need super aggressive GAC use unless there is some emergency such as a toxin event.

https://en.oceamo.com/reaktormedien2/

 

[awokenreefboy]

I've read a lot on the subject of carbon and it's connection to HLLE in certain fish (think hippo tangs), it's believed that dust from lignite carbon (from coal) is a contributing factor in the disease. I have used coconut shell carbon for ages without issue.

So this was also something that was interesting to me that Dong addressed, not specifically for Hippo Tangs, but for fish’s slime coat/gill health.

He mentioned that the carbon you’d want to use is chunky carbon, instead of carbon that is super fine. He mentioned that the dust particles that you’re supposed to rinse out is harder to do in those finer particle carbon brands, thus being released more into the water column.

 

[awokenreefboy]

GAC both adds and removes some trace elements. Christoph at Oceamo showed this for one brand (link below). Be careful in interpretation, since the experiment was done to show the qualitative effect, not a quantitative effect, because he used vastly more GAC than a reef aquarium would use.

I personally am not overly concerned because it just gets buried into the larger sources and sinks of various trace elements in a typical reef aquarium.

I do not agree that 3 days is the limit on GAC utility in most tanks. In any case, tanks do not need super aggressive GAC use unless there is some emergency such as a toxin event.

https://en.oceamo.com/reaktormedien2/

Wow! Super interesting read.

It would be cool to see what exact concentration of each media they used relative to the volume of water used… I think that would be much more practical in an everyday reefer setting.

I guess a good takeaway from this article, and correct me if I’m wrong, would be to use the exact recommended dose of GAC or maybe even half of that for your volume of water? I feel like many people make the mistake of dosing GAC by their tank size, instead of their ACTUAL water volume in the tank (ie. 20gal tank, but only 15gal water volume with rock, equipment, etc.). I’m sure in this article they upped the dose significantly to show more drastic results.

Secondly, now I understand the hate on everyday GFO use! Man, does it significantly strip both major and trace minerals from the water, but on the other hand it does remove a lot of the problematic chemicals as well.

 

[Randy Holmes-Farley Verified Community Expert]

Wow! Super interesting read.

It would be cool to see what exact concentration of each media they used relative to the volume of water used… I think that would be much more practical in an everyday reefer setting.

I guess a good takeaway from this article, and correct me if I’m wrong, would be to use the exact recommended dose of GAC or maybe even half of that for your volume of water? I feel like many people make the mistake of dosing GAC by their tank size, instead of their ACTUAL water volume in the tank (ie. 20gal tank, but only 15gal water volume with rock, equipment, etc.). I’m sure in this article they upped the dose significantly to show more drastic results.

Secondly, now I understand the hate on everyday GFO use! Man, does it significantly strip both major and trace minerals from the water, but on the other hand it does remove a lot of the problematic chemicals as well.

Christoph gives the amount used:

Then 10 bed volumes of sample solution (natural seawater, partly with element spikes) were slowly allowed to drip through the media bed.

Which means the media volume was 10% of the water volume. In a 100 gallon tank, that would mean 10 gallons of GAC or GFO or whatever. It's not intended to be realistic, but to show an effect.

I work back through the numbers for iodine binding to GAC (a popular reef misinformation that it binds to GAC).


... I've never seen any data suggesting there's so much binding of iodine to GAC in a reef tank that it dominates the consumption of iodide.

Oceamo tested this and concluded that there is some binding, but that even with the equivalent of 10 gallons of GAC used in 100 gallons of seawater, that the total binding of iodide was only about a third of the total iodide present. That means that the binding to a couple of cups of GAC in 100 gallons over the entire time it is present, would be far less than the typical depletion of iodide, which is often more like 100% of the iodide present in a few days.

A simple calculation may not fully tell the story for several reasons, including that Christoph may have spiked the iodide prior to the study to better see the binding (which potentially inflates the binding amount) but if consumed at the Oceamo rate, 2 cups of GAC used for 3 weeks in a 100 gallon aquarium would only consume 0.01% of the iodide present per day.

https://www.reef2reef.com/threads/dosing-iodine-when-using-activated-charcoal.1095478/

 

[awokenreefboy]

Christoph gives the amount used:

Then 10 bed volumes of sample solution (natural seawater, partly with element spikes) were slowly allowed to drip through the media bed.

Which means the media volume was 10% of the water volume. In a 100 gallon tank, that would mean 10 gallons of GAC or GFO or whatever. It's not intended to be realistic, but to show an effect.

:grinning-face-with-sweat: Thanks for clearing that up for me. When I first started reefing none of this in depth testing was really a thing, and now that I’m back I’m slowly catching up to speed!

A simple calculation may not fully tell the story for several reasons, including that Christoph may have spiked the iodide prior to the study to better see the binding (which potentially inflates the binding amount) but if consumed at the Oceamo rate, 2 cups of GAC used for 3 weeks in a 100 gallon aquarium would only consume 0.01% of the iodide present per day.

That’s honestly a huge relief. Seems like it’s not even significant enough to make a huge difference, if at all.

It’s a little overwhelming diving into all these ICP testing topics. Seems like EVERYTHING can affect your tank in some negative way - it’s just about balancing those effects. It’s hard to remember to not obsess about numbers when reading about all this stuff.


Thanks for your help brother!

 

[Randy Holmes-Farley Verified Community Expert]

It’s a little overwhelming diving into all these ICP testing topics. Seems like EVERYTHING can affect your tank in some negative way - it’s just about balancing those effects. It’s hard to remember to not obsess about numbers when reading about all this stuff.

Just remember, some very nice tanks have very minimal controls on various element levels. Just going with something like AFR or Tropic Marin A and K may be all most tanks need for trace elements.

 

[Lasse]

GAC both adds and removes some trace elements. Christoph at Oceamo showed this for one brand (link below). Be careful in interpretation, since the experiment was done to show the qualitative effect, not a quantitative effect, because he used vastly more GAC than a reef aquarium would use.

I personally am not overly concerned because it just gets buried into the larger sources and sinks of various trace elements in a typical reef aquarium.

I do not agree that 3 days is the limit on GAC utility in most tanks. In any case, tanks do not need super aggressive GAC use unless there is some emergency such as a toxin event.

https://en.oceamo.com/reaktormedien2/

A following up here

Sincerely Lasse