"sea water minerals."

The head on my boat has seen very little in the way of sea water minerals... first as we simply were not using the head that much (early on I wasn't sure what worked and what didn't) and because Peggie pointed out how a boat could be plumbed for fresh water flush... which IS how my boat is plumbed... so we do fresh water flushes.

However all that said, and the fact is I don't know how the previous owner took care of the boat, so it sounds like some preventive maintenance is in order.

Thanks Peggie.