Page 11 - PDZA Sustainable Aquarium Brochure

SAND FILTRATION VS DRUM to an elevation above the tank. For drum screen
SCREEN COMPARISON filtration systems, we only have to pump with just
Drum screen filtration systems have the potential enough pressure head to lift the water to the top of
for significant savings in power usage compared to the drum filter. That means they take less energy.
sand media filtration systems. Sand media filtration A summary of sand media filtration vs. drum screen
systems require pumping to drive water through the filtration is in Table 3.
pressure sand filter and pumping to lift the water

Table 3—Sand Filtration verses Drum Screen Filtration

Issue Sand Media Filtration Drum Screen Filtration

Energy use Up to 20-ft. pressure head Low pressure head of 2-ft.

Placement Any location due to conservation Must be located at exact elevation
of pressure energy for ultimate energy conservation

Filtration Well established for 30 micron Generally limited to opening
filtration and a percent removal size of 20 micron minimum with
to 10 micron or less by adherence limited removal of any smaller
particulate
Productivity vs backwash water 300 to 600 gallons filtered water 150 to 300 gallons filtered water
per backwash gallon per backwash gallon

Capital cost Approximately $50/gpm in the Approximately $70/gpm in the
600 gpm size 600 gpm size

Maintenance costs Replacement of sand media every Daily checking, weekly cleaning,
5 to 10 years. Relining of carbon monthly lubrication and annual
steel vessels after 20 years servicing of critical moving parts.

Biofiltration Nitrification is a reliable process Separate biofiltration media
well established in sand media must be provided
filters

CASE STUDY: THE PACIFIC SEAS AQUARIUM AT POINT DEFIANCE ZOO & AQUARIUM 11