Are you sure you have a 250 gallon refugium? Your total system volume is listed as being 350 gallons, but your tank is 180, the refugium 250 and the sump 80, for a total of 510 gallons. Which is it?
I think that it might be close to 350.
The tank is a 180 with minimal rock and 6" of sand
so it might be 140 gal. The refugium is a 230 it has approximatly 200 gal. The sump is 80 gal. but is a little over half full. The total system volumn could be around 400 gallons. I say 350 just to be conservative. I wish it was much more!