180 Gallon Acrylic Build Questions

[EelFan]

Picked up a 180 Acrylic tank Last Tuesday. Tank has a Coast to Coast overflow. Also picked up 3 Sea Swirls, a Skimmer, and a Sequence pump.(Pictured) Going to be running a 75 gallon sump (Tank is already drilled)

Questions
I believe the PVC pipe facing downward exits the tank and goes into the sump correct? And then through the sump and into the big PVC pipe (the return) Somewhere along this way I believe I was told that the Sea Swirls are plumbed in. Is this true?

Now onto my real question, as you can see I only have 1 pump atm and I believe I need 2, correct? Also Im in need of advice on how to build a sump with this kind of set up.
If anyone could chip in some help itd be gretly appreciated.

 

[EelFan]

Also this may or may not be the right section for this sort of post... I looked for a section dedicated to plumbing and sumps but didnt find anything (perhaps I missed it, or this is it)

 

[sbeason]

You only need the one pump. I see it is external, so you have to account for that when configuring your sump. Yes the 3 drains are connected together and run to the downward turned pipe to a sump. You can run a bigger pipe from your pump back to your tank, "Tee" it off to each of the 3 swirls. Its hard to see but the bigger pvc pipe that is turned up looks like its inside the overflow, but hard to tell from the pic.

 

[EelFan]

I will need to basically run the pump outside of the tank? Will I need to drill the tank? I may have to find an internal pump if that is the case.