Hlle

[Cole Harlow]

How do you treat hlle my blue tang has it all over him and my yellow tang has a smaall patch of it around his eyes
Thanks

[Wall_Tank]

Check for stray voltage in your tank.    If you do not have a ground probe in your tank, do that too.

If the fish is otherwise healthy, I would look at boosting the diet by soaking the foods they eat with a product like vita chem or selcon.

[The WuSue]

+1  And check phosphate levels in the tank.

[lazylivin]

What do you feed it?

[Cole Harlow]

nori mysis flake food and pellets

[lazylivin]

HLLE used to be a mystery but now is widely accepted that it is a lack of algae in the tangs diet. If that is not the case here take a look at this. Hope it helps. http://www.coralmagazine-us.com/content/activated-carbon-hlle-smoking-gun-found

[Todd W.]

Interesting topic, decided to do some digging to find out why exactly they determined Activated Carbon as a Cause of Head and Lateral Line Erosion (HLLE) in Marine Aquarium Fishes.  I am not using tradition citation in this quick analysis as it is just a PITA.
http://www.coralmagazine-us.com/content/activated-carbon-hlle-smoking-gun-found

Carbon dust exposure to humans can cause many issues
http://www.ccohs.ca/oshanswers/chemicals/chem_profiles/carbonbl/health_cb.html

So trying to determine why carbon dust would affect certain Marine Aquarium Fishes.  A quick theory following some brief research could be what is cited in this article.
http://www.aquaticeco.com/pages/full_width/111/Activated-Carbon-in-Aquaculture

Quote; "Activated carbon will adsorb the following from water: chlorine and some chloramines, many dissolved organic contaminants, trihalomethanes (THM) and phenolics, total organic carbon (TOC), oil and hydrocarbon contamination, ozone, bromic acid and total organic halogens (TOX), adsorbable organic halogens (AOX) including chloroform, colors, pesticides, odors and more. Activated carbon will also reduce biological oxygen demand (BOD) and chemical oxygen demand (COD)."

Here is my theory, Carbon Fines in the water is not the cause in and of itself, I believe that if further research was performed at more of a microscopic and microchemical level it may be found that Carbon Fines are the transport mechanism for the build up of what is absorbed by the Carbon Fines.  Once the Carbon Fines are introduced into the fishes metabolism, the fishes body then absorbs all of what is listed above; chlorine and some chloramines, many dissolved organic contaminants, trihalomethanes (THM) and phenolics, total organic carbon (TOC), oil and hydrocarbon contamination, ozone, bromic acid and total organic halogens (TOX), adsorbable organic halogens (AOX) including chloroform, colors, pesticides, odors and more. Activated carbon will also reduce biological oxygen demand (BOD) and chemical oxygen demand (COD).

This may cause an autoimmune response from the body of the fish to destroying its own cellular makup or the contaminants actually destroying the cellular makup of the fish....
 
Again, this is just a hypothesis but I neither have the time, money or resources to attempt to test.

Todd

[Cole Harlow]

ok thanks for all the help im hoping he can recover. even if he does rrecoveer he will probbaly have scars will i be able to tell a differentds between  dieseases areas and scared areas.

[The WuSue]

The tissue on the fish will mostly regrow. Our sailfin tang was a rescue out of a truly disgusting tank.... He had Hlle so badly I'm surprised it hadn't eaten his skull. He looks fine now after about a year in clean water (but there was noticeable improvement in about four weeks).  There is a bit of scarring that is much smaller than the original affected area, but it looks much different from Hlle.

[Wall_Tank]

My Blue Hippo tang had it bad when it was young.   Mostly recovered except for a hole in the gill plate......   You can still see some scaring though.

[Cole Harlow]

I recently got a ro /di system and the blue tangs doing awsome so are the corals in my tank and ive only changed 40% of the water