Possible Link between HLLE and Activated Carbon

[Ping]

This would never be published in a Scientific Journal. It is terribly written and intended to persuade the reader to a conclusion; even before a study is conducted.

First Question, who was surveyed? - Some idiot or a respected aquarist.

Public Aquarist? Is that a scientific credential (BS, MS, Ph.D.?)

Have the survey respondents been peer reviewed for credibility: MAAST and R.C. are a source of peer review for our community.

How much carbon was used and for how long was the carbon used before removal, I could go on but I am only this negative to explain a point. Just because it is written does not make it credible. Carbon is very effective if used correctly. I would postulate that most negative critics of carbon do not even know what carbon is intended to do, or how it actually works.

[Europhyllia]

Here you go. Here's an update:
http://www.coralmagazine-us.com/cont...king-gun-found

[ErikH]

I was fairly certain of this, thanks for the update!

[allan]

wow, that was a read and a half. I just started using carbon, low dust.

[alton]

Maybe someone can answer me on this study with lignite coal which I believe is strip mined. I know south of SA there is a electrcial plant that runs off of lignite coal. In this study all I hear is the name lignite coal never charcoal made from coconut shell, cherry wood, oak wood or charcoal from any other material? Also remember most liquor is filtered through charcoal to get its taste?

[Europhyllia]

Good point Alton. Post it if you find the answer

[CoryDude]

Here a a few thoughts I had while reading this article. Again, I am not discounting what is being theorized, but I'd like to see a broader study done.

1) "To date, the cause(s) of this syndrome have not been identified in aquarium fish through published scientific study, although conjecture and informal studies abound." They admit from the get-go that there still isn't a concensus as to the cause of hlle.

2) "When the survey results were limited to professional public aquarists, 19% of the respondents found complete reversal of HLLE by discontinuing the use of carbon filtration." So 100 "advanced" aquarists were surveyed. There were 18 treatment methods shown to have worked, 84% of those methods involved moving the fish to new environments, and only 19% saw a reversal of hlle when carbon was discontinued? The number of people keeps getting watered down, while the variables keep going up. Mathematically, this doesn't prove a thing to me.

3) "Three 120 gallon marine aquarium systems (two tanks per system) were established using typical home aquarium equipment and synthetic seawater. Live rock was utilized as the basis for biological filtration in all three systems. Thirty-five Ocean Surgeonfish, (Acanthurus bahianus) were evenly distributed among the three systems at the start of the study." This does not constitute a comprehensive study IMHO. A much broader study conducted in numerous settings around the country done by different experts would be needed for a more complete study. The article does state that other public aquariums have reported similar findings, but no information was given about them. This seems like too narrow of a snapshot to tell everyone to start dumping their carbon in the trashcan. Plus, a more comprehensive peer review done of a longer period of time would be needed.

4) "It has also been reported that aquariums which use foam fractionators (protein skimmers) do not seem to develop HLLE as frequently, even when carbon is routinely used." I'd be willing to bet most systems in this hobby use a skimmer. When I got into reefing 15 years ago, my first two purchases were in this order; a fish tank, a skimmer. Wouldn't this mitigate most of the threats of from carbon in the majority of systems?

5) "In addition, the hard pelleted carbon used in this study did not cause severe HLLE, while the soft, dusty carbon did." I have yet to see one reefer out there that does not use pellatized carbon. The article even states that most aquarist do not use the dusty type of carbon. Plus, I have yet to see one box, bag, or container of carbon that does not specifically state to completely rinse your carbon before using it in a tank.

The new article does not change my opinion from last year. It's basically the same thing as the previous write-up, but with an update on the results from the Toledo Zoo experiment. The people there did a GREAT job of using a controlled setup, but I still think there's too many factors, and too little time researching this for me to throw my container of carbon in the trashcan.

[ErikH]

Dont throw it away, just rinse the carp out of it. There have only been two pictures of fish in the wild with HLLE, so it's not a stretch believing that it comes from something added to our tanks. Well, what's one of the most common filters for our aquaria?

Carbon.

[Richard]

Here you go. Here's an update:
http://www.coralmagazine-us.com/cont...king-gun-found

I find that article and the study very interesting and very annoying at the same time. The annoying part of the article is that the authors are declaring activated carbon as causing HLLE when it sounds like it was the dust that was the likely the cause.

The really interesting part of the study is that they were able to cause HLLE all the fish exposed to the unwashed lignite carbon and microlesions in the fish exposed to the unwashed pelleted carbon. The annoying part of the study is it appears they didn't take the next logical step and expose a group of fish to a non carbon dust of similar size/composition to see if it caused HLLE as well. Hopefully that will be a future study.

Still it's not enough for me to stop using carbon. I've never had HLLE problems from it but then again unlike the study I never ran a tank with no skimmer, no mechanical filtration, and used unwashed dusty carbon without rinsing it first.

[jroescher]

Wonder how this would affect the use of RO units? They use carbon filters.