JennM;580627 wrote: I believe Bill (Icthyoid) has a theory about HLLE and Vitamin D... I'll see if I can find his thread.
What are your parameters? I know some will certainly disagree with me on these two points, but in my experience, high nitrate and/or stray voltage can contribute to HLLE.
You might want to check your tank for voltage. There's debate about whether this is a cause or not. I tend to believe it is, from my own observations, but others disagree. Nevertheless, it's something that *should* be addressed if it is present, regardless of whether or not it is causing obvious problems.
http://www.wetwebmedia.com/hllefaqs.htm">http://www.wetwebmedia.com/hllefaqs.htm</a>
Google around and you'll find info for and against that thinking.
Some also suspect carbon use as a cause too. Dunno...
I've got 4 tangs in my shop that came to me in advanced stages of HLLE, fins mostly gone - too gone to come back. 2 came from a tank with no water change for 2 years (water quality? diet?) and the other 2 came from 2 separate tanks where water quality and diet were ruled out, but both had faulty heaters (voltage was found in both tanks).
Over the years I've seen this many times - too many times to dismiss it as a possible cause - but I have no "science" to back it up as such.
Jenn[/QUOTE]
Without dredging up old discussions, it has been shown, scientifically, that carbon does cause it. I can dig up the references if you like. An interesting point that Jay Hemdal at the Toledo Zoo and Aquarium makes (he spearheaded the research) is that in almost every single case, if not every case, where it has been "shown" to be voltage or similar, the fish improves when it is moved to a new system, coincidentally with lesser or no voltage. However, in case where voltage is simply "removed", there is no appreciable evidence showing it did anything. This is shown , to an extant, in your cases, too, Jenn. They came to a new system when they came to you. Again, just passing along info that has been amassed and will soon be publicized (I think).