The housing unit-containing a pump, filter and LED lighting-can easily be removed from the tank for maintenance. The pump draws water from the bottom and cycles it back at the top end in a nice gentle flow, providing water circulation at a constant rate of 150 litres per hour. Two filter cartridges collect organic waste and provide biological filtration to keep the water healthy for fish and plants. They can be pulled out to rinse or replace. The aquarium includes advanced LED lighting that allows you to create a bright daylight setting or blue-tinted nighttime lighting.