Thanks for the help guys. I ended up ordering a cubic foot of resin from affordablewater.us for $110 including shipping. They list it as "Dow American Made 8% Crosslinked Cation Softening Resin", but they don't say exactly which Dow resin it is. That's okay, because even if they did say which...
I have an 8 year old water softener that is only softening to about 6 grains per gallon. This is an improvement over the city water's 20 grains, but is still not good enough because I need to protect my new tankless water heater. I had a local water softener assembler inspect my system and...