The saturated brine in the bulk of the tank is denser. Fresher water is less dense. So with slots at the bottom only, the pressure can be equal on both side of the slots. The column of fresher water in the brine tube will be higher with the pressure equal at the bottom slots. I think that after a week, the water at the slot levels will be saturated with salt. But above that level, there can be fresher water due to stratification.
I think the slots in the brine well should continue higher than is commonly done. Since slats only at the bottom is the norm, I wonder if there is any advantage to that. The slotting higher in the brine well would not seem to increase manufacturing costs much, and the weakening seems acceptable. They could use fewer slots if the mechanical strength is the reason. I think that as long as some salt is above the liquid level, and there are slots that high, the brine tube liquid should get saturated with salt too. The advantage of letting the water in the brine tube get saturated with salt would be better regeneration of the resin. This advantage would be greater with a smaller brine tank.
My thought is at the surface of the liquid in the salt area, the pressure would be lower than in the brine well tube at that level due to the elevated level of the fresher water. Flow would happen. Salt makes it into the brine tube upper levels.
Idea: drill some well-spaced 1/8 inch holes into the brine tube just below, the level of your brine in the salt. Some holes above would not hurt. If you have normal brine-last brining, you have maybe a week for things to equalize. A couple slots, made with a cutoff wheel in your Dremel tool, would be even better. Comments?
See
https://terrylove.com/forums/index....in-brine-well-higher-than-in-brine-tank.88677