The waste line just taps into the emergency overflow for my water heater. The water supply was tapped into the water heaters input.
Right now I'm going to try a Jebao DC6000 that I had laying around. Hoping with the variable speeds I can find a good speed to mix the salt and I like the way the pumps ramp up, since I'll be cycling them a few times a day to circulate the water.
My only concern is they are not designed to be an external pump, but I've read a lot of different posts where people have used them externally for quite some time. We'll see. If it doesn't work I'll find a smallish Iwaki or something.