I'll start by filling the skimmer section, and turning on the skimmer pumps and testing all the plumbing associated with that. Then I will start filling the rest of the sump and check the return pump supply plumbing. Then I'll turn on the return pump and check all the return plumbing. Next, I'll fill each of the overflow boxes and check the bulkheads and plumbing in each overflow. Then I'll fill the tank enough to cover the two closed loop supply plumbing and check all that. Then I'll turn on each of the closed loop pumps and check all that plumbing. And finally, fill the entire system and turn it all on, and open a Dos Equis and celebrate.