DIY Skimmer*Confused*

Outside cup is 6 inches and inside is 3 inches.
Yep, the Boss is old school... He got into the hobby in the 70's and yea prob did that type of skimmer in the 80's.
The salinity IS quite low actually... I'm waiting for the salt that I ordered to arrive. Hopefully sometime during next week.
Looking back at the photos, I could see how you got a bit confused... It really does look like a drain pipe on the cup. It's actually the return pipe from the skimmer column to the sump. I plan to mod my sea clone skimmers in this same manner in an attempt to get it to run more efficiently.
When I up the salt, I'll post more pics to see if that will help with the foam. S.G. as of now is 1.010:-X