Maybe you want to clean out the brine tank. Fill the brine tank one way or another, One way might be to add 5 gallons of water before putting the salt back in.
Then, for each cuft of resin, add 1.2 fluid ounces of liquid chlorine bleach mixed into maybe a quart or two of water. Pour that down the brine well, or add the bleach before adding the salt. Let it sit with the salt for an hour or so, and do a regen. My method suggestion is not polished.
One fluid ounce is two tablespoons.