plumbing request

Two things: install a water softener, and remove sludge from our water heater

1. As you know, Sunnyvale has hard water, and we are seeing a lot of evidence of it in our shower head, kitchen faucet, toilet, etc.

   • How can we best clean it out? Flush with Vinegar? or just soak the faucet in vinegar?

   • We'd like to install a water softener. I think we already have the pipes to do it, but I don't know which kind of (or brand of) softener is good. I see this in our garage; does this mean we already have the piping to do it?
     https://photos.app.goo.gl/LbEzY2DNqhKR8f9S7

   • Which brand or type? Based on a Consumer Reports article we don't want just a conditioner, and would prefer to use Potassium Chloride instead of Sodium. We're only two of us, so don't use a whole lot of water.

2. Our water heater needs to be flushed from time to time to get rid of the crud (minerals from hard water). It was so bad last time that we had to replace the whole water heater, so this time we want to get it flushed before that happens.  Do you use or recommend a device like this?
   https://a.co/d/1y2TRXs

Thank you

Ben and Keiko Reaves, 1374 Fisherhawk, Sunnyvale 94087. cellphone 650 303 1954.

Here is a photo of the pipes I found; is this from an old water softener?