that is exactly what i thought about the biomedia... so i recently added like 10 packs of scrubbies... but i guess only time will tell there... and i never even thought about the return leaving microbubbles but i reall dont think it is that... when i let me return run a little slow it oushes bubbles through and all the bubbles actually help to clear up the water... but i honestly think that this whole milky water and algae have something in common... what are some ideas on why or what would prevent algae from growing... i think there is honestly a link between the two... i could be completely wrong and off there... but the only algae that will ever show up is diatom... small and brown.... i actually did a gravel change last night because i absullutely hated the gravel in the tank so i syphoned it down into my sump (so i didnt loose my beneficial bacteria) and just added the new in... the old sand would always keep dirt and other stuff down there (being black sand i couldnt see it) and the sand i added is pool sand... and i completely love this... i really appreciatwe the response from everyone and am anxious to hear more...