Your water can't be "TOO SOFT". It's either soft or it's hard period. There are now ways to adjust for degrees of soft water. If you adjust the system to a lower salt dosage it then has to regenerate more frequently. Every softener has a certain "capacity". It may be 20k, 30k, 45, 60, etc. The salt dosage depends on the total capacity, water chemistry and water usage. Your Culligan MK 89 is a 30k capacity softener and lowering the salt dose will only cause the hardness and iron to build up on the resin thereby causing all the hardness and iron to bleed through softener in very short time. So you will NOT being doing yourself any good by lowering the salt dose.