[BCWolfen]

Thanks all, thats great.

My setup will have my 75Gal Tank, 25Gal sump, 33Gal viewable, mangrove planted refugium. My skimmer is an older ETSS (model unknown) downdraft with a 13" tall tube from bottom of box to bottom of collection cup. A 20" tall intake tube from bottom of box to air injection pipe. The intake is a 3/4" line the output is 1 1/2". The skimmer box is 9" x 6.5" x 5"
I plan to run the mak4 in a closed loop on the skimmer. Is this correct sizing or will a smaller suffice.

My overflow from my 75 Gal into my sump is a 1 1/2" pipe. What size pump should I be running in my sump's return to circulate enough water.

As I need to purchase 2 pumps I want to assure I'm moving enough water while still keeping costs as low as possible.

The 33Gal planted refugium will be added last, months down the road. I have not yet determined how I will plumb between it, the 75 Gal and the sump.

Also if anyone has links to any older ETSS downdraft skimmer's I would appreciate them. Their site only shows the newer models and I would love to get some specs on this unit I have acquired. I know its good up to at 100Gal, but that all. lol

Thanks again....