This is off-topic, but it does link in, I promise. :)
I researched some information about HITH (had two guys who looked like they might have some pitting, and wanted more information), and more and more people are believing that it's actually *caused* by a vitamin and mineral deficiency. Apparently, there are a lot of people mistaking HITH with a parasite infection (can't remember the exact name), they often present together, since the parasite will absorb all the vitamins before the fish can, but it is possible to have HITH without a parasite infection in certain circumstances.
What the other websites and aquarists recommended was to take out all filter carbon (because the carbon can also absorb the minerals), feed a very good diet either a wide mix of fresh/frozen or NLS (specifically), and to give a vitamin-c supplement. Either a vita-chem-like supplement, or even just crushed vitamin c tablets or liquids.
Long story shorter... ;) It might very well be a positive to be using the vitachem, it could help to head off some serious issues later. :)
I started using a natural water dechlorinator that is made of vitamin-c, made by the ATM company. Apparently, this stuff naturally dechlorinates without the usual dechlorinator chemicals because of the vitamin c. I don't use it normally as a dechlorinator, but I do add it when I'm adding new fish to a tank, or if anyone is acting puny, just because I figure it can't hurt. :)