I haven't gotten pictures of the mixing station in progress yet, but here is the general sketch I worked up to build off of.
The left tank will be saltwater. Right fresh filtered. I am running separate DC pumps for each. Eventually, I will tie the speed/on/off of the pumps to a remote control. With the ability to pump the water overhead to various points in the system, I'll be able to turn them on/off up/down via the key fob remote.
The tanks are plumbed so that I could potentially turn them into a 300 gal mixing station with the turn of a valve.
Otherwise, I'll pump the fresh over to the salt station and mix the salt. I can pump either up into the overhead cable tray to run across the room with the turn of a valve.
I have plumbed in 1/4" access points so that I can potentially hook up peristaltic pumps to do a slow water change in the future if I want.
I also have drain lines at the bottom I will be able to hook up a long hose to. That way I can quickly hook into the plumbing and run the hose across the floor to the drain.
The last thing are quick access taps high enough to slide a bucket under if I wanted to fill those quick.