Pike614,
The most often reported "cure" for this involves moving the fish to an new tank - one that has no history of HLLE. The grounding idea has never been proven, and it never worked in all the times I tried it. Many of the "diet change sucess stories" involved moving the fish to a new tank first (see above). Sometimes, diet changes alone have been reported to work....but not always. Vitamin C and Selco are the two most often reported nutritional additives used.
And then there is carbon dust: this has been proven to cause HLLE in many cases. Any chance that the tanks has had "dusty" carbon added to it at some point?
Jay