The mineral deposits, as long as they're not too heavy, add a nice patina to the pots, and truthfully, you'll never get them all off. They do, however, indicate that the organic material in your potting soil is just about gone and should be replaced. Also, unless you have some reason for using the saucers, I would get rid of them. They will encourage root rot and are a great breeding ground for mosquitos.

Our calcium and lime deposits were way beyond anything vinegar could address. We found a product called Diamond Magic at a local hardware store. We had a thick calcium/lime layer on the shower doors. I wound up using the product with Grade 0000 steel wool on the glass. It took almost a month to get the doors clean. I keep a microfiber cloth near each sink and wipe off all water spots after use.

From the sound of things, your well water is exceptionally "hard". The term "hard" means that the water has a high concentration of dissolved minerals in it. You should seek out an independent water testing lab and have them tell you what is in your water and how much. OR.... you could get a free water analysis from Culligan or other companies that sell water softeners but just remember that they are trying to sell you something. Products such as CLR can be used to clean up faucet aerators, shower heads, tea kettles and washing machine screens that get coated with lime but it's an ongoing process. I think that you will have to consider putting in a softener. There are softeners out there that do not need any sort of salt but they are more expensive than the regular softeners.

This is not allowed, ever! What happens when little Johnny next door goes to get a drink of water? He gets a dose of Drano and ends up dead, that's what happens. No real plumber in his right mind would put drain cleaning chemicals or lime-away into a potable water system. The fix is for the landlord to call a plumber and have the offending pipe replaced. If the landlord is insistant on putting chemicals into the potable water supply I would go to your codes enforcement officer in your town/city and let them know whats up. This is downright dangerous and someone could get hurt or killed if this is done. A lawsuit will cost the landlord a lot more than hiring a plumber to fix the problem correctly.