GAC and HLLE disease, what is your experience with Tangs?

[Liquidgold]

GAC (granular activated carbon) has been implicated in research reports as a major cause of HLLE (head and lateral line disease) in low mucus producing fish such as tangs.

http://www.advancedaquarist.com/blog/activated-carbon-affirmed-as-causative-agent-for-hlle-disease

Dilemna: how does one strike a balance between controlling the chemical warfare between corals by using GAC and preventing HLLE in our fish?

should GAC be used 24/7, intermittently, or not at all?

Matt B.

 

[newtothis]

I don't use GAC, GFO, and I've also removed my fuge from my system too. It's been offline since April/may and haven't seen any difference with or without it.

 

[SC50964]

I had HLLE happened to my blue hippo several years ago. Shortly after I removed GAC, the tang started to improve and the HLLE was gone with a week or two.


Sent from my iPhone using Tapatalk

 

[happaman]

I stopped using carbon several years ago since I had tangs. Just have a kole atm and it's doing great. Also took my GFO reactors offline. Rely on macro algae exclusively in one tank and macro and a oversized skimmer on another. I get cyano every once and awhile if I feed too much so I just do larger water changes.

 

[rayray]

That was a good scientific study by the toledo aquarium, 1 of very few in this hobby. Just because they established causation doesnt mean it will happen every time. Its like when a gene is shown to cause cancer, but not everyone who has the gene actually gets cancer. Its never happened to me in 15yrs of reefing. A separate scientific study would be need to see what frequency it occurs in the hobby.

 

[MadMax]

This particular subject is not without controversy. Its been told in upper regions of the industry that the original "researcher" did not rinse the carbon before use and that dust particles littered the bottom of subject tank. This would/could attribute to a nuisance irritant in many species (fish or not) not much different from any other foreign particulate. From what I understand, such research was also not subject to peer review or any other kind of authority to confirm the legitimacy of the results.
Such is the case plaguing our industry on many other subjects: lighting, filtration, water chemistry, etc. Literally anybody can claim to be an "expert" in this hobby and few people have a vested interest to question them. Minoring in Oceanography or Marine Biology is hardly sufficient experience in my book. (Heck even the building trades require some sort of Journeyman experience) This is not to say the information presented is false or purposely misleading, only that there does not exist a system of checks-and-balances such as those in the scientific and medical communities. Long Story Short: Be both sceptical and wary before coming to a definitive conclusion on such subjects.

 

[cymaster007]

GAC worked fine for me I utilized it for many years w/ tangs in my tank. I ALWAYS rinsed the finer particles out before actually putting it in my tank. I am a firm believer that the particle sizes of the carbon is directly related to potential HLLE

 

[happaman]

Here's the summation of the study which I find compelling. It's the 2nd one, peer reviewed. Specifically mentioned dust like Cymaster noted so rinsing may be a key variable. Also notes exceptions to the rule.

Carbon does indeed cause HLLE. Researchers once again chose to work with Acanthurus bahianus, distributing seventy-two specimens between control and GAC-treated systems (this time using extruded coconut shell activated carbon). In the treated systems, HLLES developed exponentially over 15 days, progressing from the tangs' chins, then cheeks, then expanding and coalescing outwards. Once the GAC was discontinued, the HLLES reversed in a mean time of 49 days, regressing in opposite linear fashion as the progression.

Furthermore, Jay Hemdal provided Advanced Aquarist some anecdotal information from a researcher who found carbon dust in the lateral line of some fish suffering from HLLES using electron microscopy. The researcher emailed Hamdel: "The theory was small sharp <carbon> dust particles would get into lateral line and bounce around because of the hair cells causing the erosions and subsequent fibrosis."

 

[rayray]

Researchers considered carbon fines as a possible cause since at least 1988.

http://www.reefkeeping.com/issues/2005-06/sp/

Or search RC, lots of opinions there from doctors of veterinary medicine.

Click the link to the Journal of Aquatic Health to read the actual research paper
http://www.advancedaquarist.com/blog/activated-carbon-affirmed-as-causative-agent-for-hlle-disease

Best part of having a reseach paper is you can replicate the experiment yourself

 

[Tangwich]

I had posted a similar article a few years back but me personally, i have not experienced hlle due to gac.