Upgraded to a Tunze 9006 from my swc120 on a 16 month old 65gal fully stocked sps tank.I installed the skimmer 7 days ago.Its in 8" of water in sump.I opened the air screw 3 full turns and left for a week,as of today still no foam at all?. When I try to open the air screw more than 4 turns the skimmer makes a jet engine noise that is very loud.I know it takes time for skimmers to break in but after a few days shouldn't there be at least a little foam??