Head and Lateral Line Erosion (HLLE)

[Jay Hemdal Verified Community Expert]

@Jay Hemdal Can you comment on my last post? I am interested in what you think good tang safe alternatives to activated carbon for the purpose of water clarity?

Water changes are always safest (grin). I've not had issues with Chemipure or pelleted carbon...but I did NOT test those the same way I did with the soft carbon study that I ran.

Jay

 

[DCR]

I totally believe the study. Back in the 80's, I ran fish only tanks with under-gravel filters and often ran cannister filters with cheap carbon commonly available in fish stores at the time. I am sure it was lignite based. I was also pretty lazy about rinsing the carbon. I was constantly frustrated with HLLE on my tangs and angels. I was really about to give up on the hobby because of it.

At one point I purchased a new angel fish and then a few days later recharged a cannister with fresh carbon. Within days HLLE started strongly developing on the newly acquired fish. I stopped using carbon after that. but it was not until I went with more natural forms of filtration (initially mud beds) that I was able to effectively avoid it.

I suspect there are other long term causes, but certain types of activated carbon can bring it on very quickly.

 

[brwaldbaum]

Sorry - I missed your post. I have NOT tried using a diatom filter to remove carbon dust, but anecdotally, tanks that have a good way to remove POC (particulate Organic Carbon) also seem to have fewer issues with HLLE. Two POC export mechanisms that *seem* to help are protein skimmers running really wet, and then, reef tanks that have corals and other inverts that tend to remove POC. In both these cases, HLLE seems to be less of an issue, regardless of carbon use (unless the carbon is dusty/soft or used in a reactor). Well rinsed pelleted carbon, used sparingly in a good reef system isn't much of a problem.

Jay

Have you ever had a case of HLLE that you suspected was due to copper use alone?

 

[Jay Hemdal Verified Community Expert]

Have you ever had a case of HLLE that you suspected was due to copper use alone?

No - I treat all my incoming fish with a minimum of 30 days of coppersafe and we have no HLLE in our systems. I did have a suspicious event 30 years ago when I was dosing copper/citric acid. I got the dose too high, and the fish developed HLLE. The trouble is, I had used carbon to reduce the copper level (grin). I suspect that this sort of thing is the root cause for people thinking copper caused their HLLE, they often use carbon to remove the copper afterwards, but when the HLLE develops, they don't think it could have been the carbon, and just blame the copper. BTW: carbon isn't even very good at removing copper....

Jay

 

[brwaldbaum]

No - I treat all my incoming fish with a minimum of 30 days of coppersafe and we have no HLLE in our systems. I did have a suspicious event 30 years ago when I was dosing copper/citric acid. I got the dose too high, and the fish developed HLLE. The trouble is, I had used carbon to reduce the copper level (grin). I suspect that this sort of thing is the root cause for people thinking copper caused their HLLE, they often use carbon to remove the copper afterwards, but when the HLLE develops, they don't think it could have been the carbon, and just blame the copper. BTW: carbon isn't even very good at removing copper....

Jay

How about epithelial thinning in, say, a Zebrasoma tang?

 

[chadfish]

Has there been any follow-up studies that look at the particle size of the fines that cause the problem? If the output of a GAC or, Extruded Activated Carbon (EAC) reactor were to be filtered, what size filter is needed?

 

[Jay Hemdal Verified Community Expert]

How about epithelial thinning in, say, a Zebrasoma tang?

I’ve not seen it, but I can’t rule that out since I really don’t know the cause of epithelial thinning.
Jay

 

[Jay Hemdal Verified Community Expert]

Has there been any follow-up studies that look at the particle size of the fines that cause the problem? If the output of a GAC or, Extruded Activated Carbon (EAC) reactor were to be filtered, what size filter is needed?

No - that hasn’t been tested.

Don’t forget, the carbon fines idea is just my theory, the other researcher (Dr. Stamper at Disney) thinks the issue is carbon removes organic compounds that then are not available to bind with heavy metals, causing poisoning in the fish.
I still think I’m right about the canon fines, but couldn’t quite prove it with the study I ran.
Jay

 

[chadfish]

No - that hasn’t been tested.

Don’t forget, the carbon fines idea is just my theory, the other researcher (Dr. Stamper at Disney) thinks the issue is carbon removes organic compounds that then are not available to bind with heavy metals, causing poisoning in the fish.
I still think I’m right about the canon fines, but couldn’t quite prove it with the study I ran.
Jay

I imagine it would take a pretty in-depth study to prove the pathology.

 

[brwaldbaum]

I’ve not seen it, but I can’t rule that out since I really don’t know the cause of epithelial thinning.
Jay

Is epithelial thinning what we're seeing in captive-bred tangs, or is it true HLLE?

 

[Jay Hemdal Verified Community Expert]

Is epithelial thinning what we're seeing in captive-bred tangs, or is it true HLLE?

Some of the yellow tangs I've seen have grown out of it, so I think it is epithelial thinning. However, if you see that AND fin erosion (how YT show HLLE) then it is true HLLE. I wish I had more time to do further studies though....

Jay

 

[salty joe]

FWIW, I've been using ROX 0.8 carbon. I added a couple juvi blue ring angels in March and they both look great so far.

 

[brwaldbaum]

Some of the yellow tangs I've seen have grown out of it, so I think it is epithelial thinning. However, if you see that AND fin erosion (how YT show HLLE) then it is true HLLE. I wish I had more time to do further studies though....

Jay

Not a YT, but I do see some fin erosion. Would you classify this as true HLLE?

 

[Jay Hemdal Verified Community Expert]

See the notch in the caudal fin? That could be a nip, but it also could be a secondary symptom of HLLE. The photo seems to be taken with a flash, I think that changes how the lesions appear in real life. In the end, I can’t really say which syndrome this is, but I would NOT bank on being able to fix it after buying it.
Jay

 

[brwaldbaum]

Some of the yellow tangs I've seen have grown out of it, so I think it is epithelial thinning. However, if you see that AND fin erosion (how YT show HLLE) then it is true HLLE. I wish I had more time to do further studies though....

Jay

Do scopas tangs present the same way as YTs with HLLE?

 

[Jay Hemdal Verified Community Expert]

Do scopas tangs present the same way as YTs with HLLE?

From my limited experience, yes they do. Oddly purple, black longnose and gem tangs show more normal HLLE.
Jay

 

[brwaldbaum]

From my limited experience, yes they do. Oddly purple, black longnose and gem tangs show more normal HLLE.
Jay

Is there a predictable amount of time that passes between introduction of carbon and the first appearance of symptoms?

Is there a predictable amount of time past which the fish will not recover if moved to a "clean" tank?

 

[Jay Hemdal Verified Community Expert]

Is there a predictable amount of time that passes between introduction of carbon and the first appearance of symptoms?

Is there a predictable amount of time past which the fish will not recover if moved to a "clean" tank?

In my study, (as I recall, it was a decade ago) the first visible symptoms showed up in 45 days. However, we used dusty carbon, and if you are using a good grade of pelleted carbon, it will take longer. Our pelleted carbon control didn't really show lesions that were visible, only showed under histopathology.

No predictions regarding benefit from moving the fish to a new tank, and if the symptoms will resolve or not....it seems to have to do with the size of the lesions, larger ones just don't heal well.

Jay

 

[brwaldbaum]

In my study, (as I recall, it was a decade ago) the first visible symptoms showed up in 45 days. However, we used dusty carbon, and if you are using a good grade of pelleted carbon, it will take longer. Our pelleted carbon control didn't really show lesions that were visible, only showed under histopathology.

No predictions regarding benefit from moving the fish to a new tank, and if the symptoms will resolve or not....it seems to have to do with the size of the lesions, larger ones just don't heal well.

Jay

Does moving a symptomatic fish to a carbon-free tank reliably halt the progression of the erosion?

 

[Jay Hemdal Verified Community Expert]

Does moving a symptomatic fish to a carbon-free tank reliably halt the progression of the erosion?

It depends. The carbon free tank has to have a total history of no carbon use. Many people feel there are also other causes for HLLE. Trouble is, none of those causes have been proven. If at some point, one or more of them are studied, then they would also have to be mitigated. I've tested a few of the alternative ideas - I think I can rule out stray voltage as well as dietary enhancements (as a cure). I'm still not able to rule out heavy metal toxicity and truly deficient diets.

Jay