OK guys, I'm really disappointed with the no opinion thing regarding placement of unions and valves. Here is what I'm thinking:
One union before the chiller.
One valve going to the chiller to control the flow.
One union before the "T" to the refugium.
One valve going to the refugium to control the flow.
I'm thinking about running 3/4" pvc for everything.
Does that sound about right? Any other things I might have to add or think about before putting this all together?