Ok, i got sick and tired of that noise from the skimmer so I designed (based upon various air chambers from Nyos and others) and 3d printed the new Red Sea skimmer air chamber. After about 4 prints fine tuning (each print takes 6 hrs!), its done. Works amazingly well. Practically eliminated the noise coming from air suction. And, printed in red PLA, so matches well. If anyone is interested, send me pm.