Drinking water

[thinwater]

Thinwater -- about your point #2 "filter the fill": Here is what my friend told me they do:
"We carry two water filters: A refrigerator filter mounted between the water tanks and the sink faucets. A similar filter with hose connectors which we place between the hose and the nozzle when filling tanks. We use a SHURflo (RV-210GH-KDF-A) Garden Hose Filter(available from Amazon)"
Does this SHURflo correspond with your 'filter the fill'? I'm not sure what you mean by a dock-side filter, which sounds pointless, but I'm curious where a dock-side filter would be physically located.

Some folks mount a filter on the dock, right next to the hose connection, and then use a hose from there. Not really functional.

The Shurflo filter will work, but Camco sells this (https://www.walmart.com/ip/Camco-Water-Filter-with-Hose/14504321) through Walmart for 1/2 the price. Very similar. But both remove chlorine, which you do NOT want. Silly, really. There is a better answer.

(In the pic the filter is actually set up for rainwater off the hard top, but it works just as well for hose water. The deck fill is under the filter.)
My real favorite is what I call a "Baja water filter." It is basically a DIY PVC holder for a standard cleanable 1 micron polyester bag filter (trade size 4) you can buy for a few bucks and can wash repeatedly. A wonderfully flexible filtration tool for the cruiser, it works for hose water, rainwater, and jerry can water.
http://sail-delmarva.blogspot.com/2014/06/drinking-water-filtration-short-version.html

It's described in the post above, in a link in that post to an article, and "Keeping a Cruising Boat for Peanuts," below.