nexodos - nice skimmate - I also ran my 130D stock, with the stock skimmer & having learned all the little tricks (water lever, flow, cleaning neck, body and orifices regularly - might add I do this with my RSM 250 skimmer too) I was always satisfied with my stock skimmer, but with out any mods, it was loud (relatively / subjectively) and for mine to preform well, I have to clean neck, weekly, body monthly & orifices in the pump every few months - I have posted lots of tips on making the stock 130D skimmer preform - Cheers - thanks for sharing !
Andy - nice mod - I have read several have done this... all most all the noise with the stock skimmer comes from it sucking air (if you turn air off, it's very quite), in the RSM 250 Red Sea built a little box inside the skimmer cup to solve this & work as a silencer, the airline goes into this small box ... another nice mod is the pill bottle silencer, I know Terry has posted several links to it before... I can see where it would work well too, to silence the air intake.