i set up my new berlin skimmer in-sump..this was really an accident and i dont know why i never thought of this before...i positioned the skimmer feed pump right below the drain pipe from the main tank above. this drain pipe creates LOTS of small bubbles when it falls into the sump. the pump sucks them right in and creates immaculate bubble-ry in the skimmer! haha ..obviously someone has done this before but DAMN its working wonders! the skimmer is made of clear plastic so you can see all of the micro bubbles rushing through it and the cup fills with skimmate at ridiculous speed, hell of a lot faster then my aqua c. this pretty much defeats the need for needlewheel or impeller mods, as well as venturi feeds. interested to know if anyone else has done this? will take some pics if you want to see