If you use the amount of Iron Out I told you and do it as I instructed, all the Iron out will be rinsed to drain during the 2nd backwash and then the final rinse. And actually I don't know how you'd have any left in the softener if you used as much as say 5 lbs. It will all be rinsed out while none can be introduced to your water plumbing. There is no need to do more 'rinsing' than that and if you did, you are using capacity and salt needlessly. Fear is usually caused by not knowing facts and reacting to fears causes problems. Let her read what I've said and if she still has questions ask and I'll answer them. Unless there is something wrong with the softener, IO or salt or dirt in the salt tank that is next to impossible to suck it out of the tank, can not be left in the softener. And if there is any of that stuff left in the softener, you will smell IO and taste salt. The dirt is backwashed out of the resin bed, but then you find out what is wrong with the softener and fix it.
Removing sulfates and chlorides is very expensive. You use an anion type resin in a softener configuration and regenerate with softener salt. It should be solar crystal salt. Pelletized salt builds up in the bottom of the salt tank displacing water to cause more build up which requires cleaning every year or two. The same for potassium chloride salt substitute but it is worse than salt pellets.
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