This study was carried out to evaluate the variations of headloss rate and of specific deposit to depths with effective size of media and configuration of filter layer during algae blooming period. 0.51mm size media was disqualified because most of headloss occurred rapidly below 5cm from surface layer however 0.91mm size media acted deep filtration more than 20cm from top, as result 0.91mm sixte media filter had 2~3 times longer filtration time than 0.51mm sixte media filter, but 0.91mm size media have break-through potentiality. multi-layer filter with 1.02mm anthracite and 0.51mm sand had large deposit volume in upper layer that could longer filtration time, moreover smaller media in lower layer that could protect break-through.