HD5 I had rust, calcium, sulfur, lime and whatever else in mine. I also HAD galvanized pipes. That said, I put in an electronic whole house filter by Morton, purchased at Menards for $350. We can now drink the water, make ice and don't have to soak screens in CLR anymore. Not positive if getting rid of the galv. pipe or adding the filter did the most good, but it made a HUGE difference. I put it before my softener and faucets, but after my outside faucets. We still see rust and smell sulfur outside in the hose, but nothing inside the house. That and a 30 plate w2w exchanger and neverending hot water. I have not had to clean anything in more than a year. Washer and DW runs better too.