RO/DI with water softener questions?

[Reefer1978]

Was this well water? Unless the softener removed CO2 in some way that was significant, I think the result may not be generally applicable since I do not believe there's a mechanism for a softener to increase the RO membrane efficiency.

No, not well water, but New Jersey water, notorious for bad taste and hardness.

I don't know what it fixed, but it fixed something. :-)