Need help with regenerating tank

[JesseFrank]

I have a water softener filter with automatic valve which regenerates at set time.

To the filter is a large brine tank connected via a small tube.

So when regenerating, the filter sucks the brine out of the tank through the tube, then in the next step the filter does slow rinse and at the same time refills the tank with fresh water through that same tube.

The problem now is that the slow rinse time has to be set at a particular time, and during that time it supplies more water to the tank than the tank can hold. I can't reduce the size of the tube, because that would also limit the brine it sucks out of the tank.

So I need to find a way that blocks the water supply as soon as the water in the tank has reached a certain level. A floating valve will not work, because next time the filter needs to regenerate, the floating valve will still be closed and the filter will not be able to suck the brine out of the tank.

Any suggestions for this ? Keep in mind that we are talking about brine, so the material used should be brine resistant.

[JesseFrank]

That isn't really an option since the time of slow rinse has to be as long as possible, because it is the soaking time that regenerates the resin.

If you extend the time it sucks the brine to accommodate to the amount of water it refills, you're also wasting salt.

During the last rinse it doesn't supply any water to the tank in my situation.

[JesseFrank]

Bump