new here. 29 gal freshwater. python vacuum doesnt seem to be picking up ALL the waste.

hi. ive set up a 29 gallon freshwater. aquaclear 50 filter. 200w heater. tahitian moon sand. few pieces of driftwood with some anubias attached.

its stocked with 8 tetra glofish and 8 zebra danio glofish. theres also one albino bristlenose pleco.

http://aqadvisor.com/AqAdvisor.php?AquTankName=&AquListBoxTank=Choose&AquTankLength=30&AquTankDepth=12&AquTankHeight=18&FormSubmit=Update&AquListBoxFilter=Aquaclear+50&AquTextFilterRate=50+&AquListBoxFilter2=Choose&AquTextFilterRate2=N%2FA+&AquFilterString=driftwood&AquTextBoxQuantity=&AquTextBoxRemoveQuantity=&AlreadySelected=200909300022%3A8%3A%3A%2C200912171330%3A8%3A%3A%2C200912111343%3A1%3A%3A&FilterMode=Display+all+species&AqTempUnit=C&AqVolUnit=gUS&AqLengthUnit=inch&AqSortType=cname&FilterQuantity=2&AqJuvMode=0&AqSpeciesWindowSize=short&AqSearchMode=simple

my problem is that i bought the python vacuum:

http://smile.amazon.com/gp/product/B000255NXC?psc=1&redirect=true&ref_=oh_aui_detailpage_o01_s00

but it doesnt seem to be picking up ALL the waste at the bottom during my water changes. i end up doing about 30-40% water changes because im sitting there trying to vacuum stubborn fish waste up. i see your aquarium pictures and they are IMMACULATE. mine doesnt get that clean even right after vacuuming. i dont want to keep vacuuming trying to get the waste because 30-40% weekly water changes is already way too much. any advice? the pleco is only about 1.5" right now. i think my waste situation will be a disaster when he grows to his 6" max length.

thank you in advance.