Greywater system for laundry - troubleshoot with water softener system

Hi Folks.

I am seeking advice on greywater usage for plant and trees.  Our water has a salt based water softener system.  I have considered switching to potassium based system - the cost might be doable, but I have also heard this might not be good for a greywater system either.

I could eventually just bypass the system and hook up washer with cold.  

Or dump the water down a gravel driveway.

Thoughts?

Thanks
Brian