I'm looking for a water filter that could filter medium volumes of water for a family of six, something that could filter and collect rainwater or river water. It doesn't need to be portable since I intend to use this from my home, but not too large, in case I do need to transport it.

The emergency would be in case our lovely psychopath neighbors to the east do something stupid, so something that could run without electricity or power would be perfect.

https://www.katadyngroup.com/ca/en/solutions/Water%20Treatment~s5130/overview

They’re from swiss and well known for the filters and chemical products

I second the katydyn filters-I used them guiding and doing long outdoor expeditions for decades. They're high quality and effective. I specifically like the gravity bag type filters because they have high capacity but are also very portable. The Ceradyn also looks great, tempted to add that to the fleet for our house and car camping...

This looked nice.

https://www.katadyngroup.com/ca/en/2110070-katadyn-drip-filter-ceradyn~p6742

Perhaps you could suggest you favorite model? Just so I can compare

I have an old (like ten years old) model of their roll up coated nylon bag filter. I think the ceradyn is probably better for your application if more expensive and less portable.