While the cause of hlle is still not been pinned down, i've had some success by improving/ enriching the diet of those with it. To do this I soak my foods in zoecon or selcon and vitamin c. I have seen this stop and in minor cases even reverse hlle. Do you feed algae at all? ie nori? I have read of treating with metronidazole, but have not had personal experience. look at water chems, and food. some say stray voltage, but grounding probes will only create more of it, two different metals in seawater and all, nothing but snake oil. Hope this helps.
