BobNH, how does another allbeit much larger, or a much larger replacement, pressure tank get him flow of 50 gpm? What pressure is required to get him 50 gpm flow into the tub and multiple shower heads from the basement to the 2nd or 3rd floor bathroom?
Is his present pump and pressure tank capable of refilling that new larger tank so he has water for other uses while the shower is running or the tub is filling? I think not but I know fer sure the softener and UV aren't sized for the flow; simply because he is changing the bathroom fixtures and adding to them.
Treating the water with the present equipment, before it goes into an atmospheric storage tank is an option IF the softener is correctly sized now for his present peak demand flow rate; which most are not and I doubt the UV is much more than an 8-12 gpm model. Otherwise the softener is misapplied. IF so, then a new softener is in his future ESPECIALLY if we are running that water into an atmospheric storage tank at open discharge, ot we throttle it back t othe SFR gpm of the softener. And either way, the water in that tank will not hold quality, so treatment after that tank, such as UV, will be required, and that will have to be at 50 gpm. Agreed?
Also, constantly starting and stopping a pump is much more engery deficient than starting it once and allowing it to run until no more water is being used; that is much more energy efficient. Plus it extends the life of the motor/pump.
Gary
Quality Water Associates