Plumbing – What are the practical differences between 1/2“ and 3/4” pipe between a water softener and water heater

It is important to understand the reason for grounding/bonding the water pipe system in a house. The electrical service panel is typically grounded via an 8 ft or more ground rod at the meter and/or panel AS WELL AS via a bonding conductor to the metallic water source pipe. (Plastic feeds are not bonded.) The grounding wire is typically #4 copper.

The grounding of the water pipe is not necessary for the proper grounding of the electrical system if there is a separate earth ground supplied (ground rods, etc.), however it is necessary in order to assure an equal ground potential between the electrical system and metallic plumbing system.

The reason for having both the electrical and plumbing bonded at the same potential is to eliminate any possible voltage potential between the two when electrical appliances that contact water are used (electric water heaters, ice makers in fridge, garbage disposals, etc.), and to deal with any accidental contact of voltage to the water system. If this was not done, it may be possible for voltage to appear on the plumbing fixtures.

Regarding your first question about bonding the two sides of the water softening system, the recommended bonding is to assure the upside metallic system is at the same ground potential as the downside piping, for the reasons described above.

Okay I will try my best on this one. Living in an arid climate does create quite the change in temperature, do you ever get below freezing there? Code up here is at least 18" underground and sleeved if the water line is not approved for underground. I would suggest PVC sch80 pipe as I believe that is approved. The pressure loss is also minimal for the length of pipe in PVC but the number of elbows you are proposing, which I am counting 9 is a total friction loss of about 38 feet of head which is 16 psi. Now I am not saying you'll loose that much off the piping but the calculation suggest it. That is the garage application. Now on average from a water softener you will also lose about 5 psi. I understand the aesthetics your house is important, but I would keep it outside behind the fence if you guys down there have weather that doesn't go below freezing. If you do I would box it and put heat trace on the softener and lines. I hope this helps.