[spiderplant]

It's completely normal. Minerals dissolved in the water come out of solution when you boil it. The amount of minerals in the water varies a lot across the country - generally the south-east has the most because the rainwater filters through chalk. I wouldn't have thought Swansea had that much. I assume your water comes from the Welsh hills. But whatever the amount, it's harmless. Possibly even good for you.

Misty glasses are most likely caused by putting them in the dishwasher. Dishwasher detergent is very harsh. You can't solve it once it has happened, but handwashing glasses will prevent it.

ps. Glad you are back. Hope you are doing Ok.