We just installed a whole house filter for a specific problem coming from our well...a sulfur odor. The filter also removes iron. It is called a clear choice filter and was installed by ClearWater systems (no, I have no connection or interest in the company). We are now absolutely ecstatic with our water quality which for the first time has no odor and tastes good. We still plan on keeping our spring water delivery until we eventually get reverse osmosis for drinking water, but the odor from the house water had bothered us a bit when showering or brushing teeth. The odor/iron filter was placed upstream of our softener. Good luck! Soto.

The filter and softener each will have losses depending on how much flow you're trying to push through them. So, yes. And placing a section of 3/4" line in the middle of a 1" line will also reduce the pressure, especially since you'll probably have a lot of fittings to get into/out of your filter. You'd get the least pressure loss by piping up to your filter with 1" and then reduce to 3/4" at each connection.

@Bob Ack "Do you know what the difference is between various expensive branded water softeners that are salt-based?" To be clear, all softeners are "salt based". If they don't use ion exchange to remove hardness ions and replace with sodium, it's not a softener. The answer to your question is "Not much". There are only a few major components to a water softener: The control valve. Two of the best brand of control valves are Fleck and Clack. Both are widely available, reliable, and have a big installed base. Fleck is available on the web while Clack is not. Resin. There are some different types of resin, depending on chlorine levels, iron, etc. At one time the best quality resin was coming from DuPont - but most is being sourced from China now. The tanks, distributor screens, etc. It's very easy to build your own softener using off-the-shelf tanks, resin and control valve -- and that's what many local water treatment folks do. Since a good quality water softener with a Fleck valve can be purchased on Amazon for about $800, there just isn't a lot of profit to be made in that business. That's why there's been a boon in "High-End" water treatment that is mostly snake oil.

We've had whole house softeners in every house we've owned. Our soft water is great. I've never found washing my hair or anything else to be ridiculous. Could be you're not used to soft water so it seems different. Definitely must have the water tested to see what you're dealing with and as someone else mentioned the outside spigots bypass the softener. At our house in the city the kitchen cold water doesn't go through the softener. I guess the idea is that you have unsoftened drinking water. Our lake house doesn't bypass the kitchen cold and that's what I prefer. Otherwise you still have mineral deposits around the sink, coffee maker, etc.