mhmm every 2 weeks i flush. good info sir. i also use a couple airstones in my 75gallon reservoir... and an extra water pump to keep the water moving around... of course i have all of it on a timer so the airpumps/water pump turns off when the actually water pump pumps to the flood tray
you wouldnt catch me dead filling up my reservoir without this http://www.greenhome.com/prodpix/PS_hosefilter_detail.jpg
chlorine filter ftw! seeing as i CANT wait 24 hours for the chlorine to go away this is a must.
goto your local hydro store they're about 40dollars but well worth it... one...