Need help configuring tank, switch, csv

[GT diy]

I am adding a home to my well and need help with configuation. The existing home is supplied by a 1hp submersible pump with 230 feet of head and is about 100 feet from my house. I have an 85 gallon bladder pressure tank set at 30/50. The new house will be tee'd in about 10' from well and go up a hill 100' head(vertical) with a run of 230' total. I ran a hose from my house up the hill to water cure the slab and the pressure was just a trickle. A friend suggested moving pressure tank and switch up the hill to new house. I am concerned about water hammer with reverse flow to existing house. Should I install two tanks, move switch, install csv, install pressure reducer??? Any help would be appreciated. Well is deep enough to support two houses. Is 1hp adequate and how can i configure? Thx
GT diy

[Cary Austin]

100' in elevation is the same as 43 PSI, round up to 50 PSI for friction loss. So to get 50 PSI at the top of the hill you will need 100 PSI at the bottom. Your 85 gallon tank holds 25+ gallon of water at 30/50, but with 90/110 pressure switch setting it will only hold about 13 gallons, which is still plenty when using a CSV. I would leave the tank and switch at the bottom where the power is, and just set the CSV at 100 with a 90/110 pressure switch setting. The CSV will need to be before the tee to both houses. Leave the tank at your house and make sure there is not check valve in the line and it will work for both houses. But you will need to put a pressure reducing valve like our PRV1A on the line going into your house so you can reduce the pressure on that line from 100 to about 50 PSI.

Oh and you will most likely need to switch the pump to a 1.5HP, 10 GPM series to build that much pressure. A 7 GPM, 1HP would work, but I doubt that is what you have.