You are using 2.56 oz of DQ Cure #1 per gallon of water, plus salts and sugars, well within reasonable and acceptable levels. You are injecting into a boneless pork loin which is about 3" across average, or 1.5" from the center to the outside edge and immersing in the brine, cutting that thickness in half, so you're getting a curing depth of about ¾ of an inch to penetratefrom the inside-out and from the outside-in, which could be achieved with a 20% pump if it could take that much, that would be quite a lot. It is entirely possible for it to cure in 24 hours.