Help With My Filter?!?

[fishmad135]

Well i have had my tank for about 9 months now. It is a tetra easy crystal filter box. Over the last few days it has stopped sucking up water like it used to?? i changed the filter cartridge last week.

Any way do you no how to turn it up or do you have any ideas why it isnt sucking up water. Any help will be very very much loved!