davelin315
10 & Over Club
I use Black Diamond reef carbon. I don't think it has anything to do with absorption of trace elements...
teesquare,
There seems to be five different manifestations of "HLLE":
1) Typical marine fish HLLE. Carbon use is a very common cause, but because it is so commonly used, it is then difficult to determine if it is the sole cause. As I like to say, the single underlying commonality seen in ALL cases of HLLE is the presence of di-hydrogen oxide (umm - water!). Seriously, this has been the reason people have implicated such things as copper use, stray voltage, poor diet, lack of sunlight, etc.
2) That exhibited by yellow tangs. I'm not sure if the causation is the same, because the symptoms are so very different.
3) A similar problem seen in aquacultured sea basses in Australia. This is sometimes seen in long-term captive groupers. The facial pitting is more localized.
4) Freshwater fish HLLE (oscars, discus, etc.) probably caused by Hexamita protozoans in the fish's gut that may reduce the bio-availibility of some nutrients. This is the only HLLE that can be reduced by drugs - metronidazole in particular.
5) A more general pale coloration of the fish, without distinct pitting, but with some fin erosion. I'm not sure this should even be described as HLLE.