You obviously know a ton about this stuff, so wondering if you can help me understand. Whenever I travel to either coast the water always seems excessively soft, and slippery. Any particular reason? I prefer hard water just because after you've rinsed off, it doesn't feel like you still have soap on your hands and skin. Soft water is so slippery that it always feel like your hands/skin are still soapy. Why is that?
I'm not sure I can completely answer your question. I think perhaps it is partly a matter of preference, and just what each of us considers to be "normal." Soft water = more suds. In addition to hardness, there's also pH, and that has an impact on how our skin reacts.
Water is complicated. Some localities have municipal water, some folks get water from a personal well. On top of that, many houses have in-home water filtration systems or water treatment devices.
Much of what is in say, well water has to do with what minerals/chemicals are dissolved in the water, and those levels fluctuate (every times it rains).
My knowledge of water comes from experience with aquariums. In short, most tap water is toxic to fish. Fish can't tolerate chemicals to the same level human can tolerate them.
For aquariums, the best option is to initially add highly filtered water. Another so-so option is to use bottled distilled water but that us usually shipped in plastic bottles. Plastic = chemicals that probably aren't good for any creature. One can also treat (tap) water with chemicals, but, that's adding more chemicals. IMO, fish are a little like canaries in the coal mine. Water that kills fish? Might be okay for us?
Pool water is not only treated with chemicals, it is also filtered. I don't know much about pool filters, but aquarium filters have 3 levels of filtration: 1. filter big particles with a medium (fiber or sand). 2. filter chemicals by pumping water through charcoal. Charcoal removes many chemicals. Many refrigerator water filter cartridges use carbon. And #3. bacterial filtration.
In an aquarium, the very best, most natural way to keep an aquarium clean is to create as much of a complete ecosystem as possible! As an aquarium becomes established, bacteria and other microorganisms multiply. They are the real powerhouses! Ideally, every aquarium, pond and natural body of water has a balance of fish, plants and microorganisms. Over time, I found the less I changed the water or disrupted the natural system, the better.
That goes against what most pet stores tell newbies, because water changes = buying stuff (to fix problems).
Some aquarium maintenance can't be avoided. For example, the giant aquarium in Epcot looks awful, and is DESPERATELY in need of a massive cleaning/restoration. There is way too much fake plastic in there. I don't think it has any live coral at all. The plastic stuff long ago faded, and has been covered with algae for years. That giant aquarium is ugly and dingy!
If you want to see a neat little product, look up something called an Eco-Sphere pod. They are completely self-sustaining for years, as long as the shrimp live. (The brand name "Eco-Sphere", not the generic eccosphere or anything on Etsy.)
The pool might be filled with more pee than water.
