I have recently switched to Potassium Chloride instead of Sodium Chloride to regenerate my softener. Sodium Chloride used for the water softener shouldn't cause any problems, unless the salinity is way high for some reason. Iron is a different matter, "oxidized" iron (rust)particularly can be toxic. Do a google/yahoo search for "Iron in aquarium water articles" "along with the other elements that are of concern. Even the water softener question. As far as the african cichlids, if they are rift lake cichlids a higher pH and water hardness is best. Other african cichlids, like Kribs, like neutral pH. For better info go to the link below. If your keeping Kribs go to www.thekrib.com, To add the Krib has alot of good articles on water parameters for any fish. Good Luck.

Here is a link that might be useful: The cichlid forum