Changing the BLFC and injector has nothing to do with any kind of efficiency and the injector is usually dictated by the size of the tank. the BLFC controls how much water flow into and out of the salt tank per minute.
One gallon of refill water dissolves 3 lbs of salt (actually 2.7 lbs but call it 3).
As we see, micro managing causes hard water leakage and in many instances what you think is saved (water and salt) is eventually used up plus additional water and salt to fully regenerate the resin back to max capacity.
Now you must do 2 manual regenerations at the max of 15 lbs/cuft of resin, one after the other with no water usage during or between each regen so you get all your resin regenerated or you live with hard water getting through the resin bed. before you do them you should go back to the original BLFC and injector.
Then click on the Sizing link in my signature and learn all about salt efficiency and reprogram your 7000 for 60 gals/person/day plus a 24 hr reserve unless the 7000 has variable reserve. And figure a max of 30K per cuft @ 15lbs/cuft.
You don't need new or a different brand of resin, just learn to program correctly and for 7-9 days between regenerations based on the K of capacity needed for say 8 days with no reserve IF the 7000 has variable reserve, otherwise one day of reserve at 60gals/person.