otp 1000

I have an older octo skimmer that came with my used tank. The skimmer looks great and is in A condition, I'm not able to get the buble flow to maitain a steady or consistant flow. i am thinking the pump has slowed the flow rate over time. I an listing the pump info below and I would like to know if I can replace the pump with a higher flow pump. (2000,3000) I think the current one is rated at 250 gph. The tag shows:

Octopus Turbine Pump
Power:18w
Voltage:110v
calibre: 14.5mm
Max Jet: 1.6m
Max Flow 1000 L/H
weight:1.0kg
Size:132:x98x150mm

All may not be exact as the tag is worn. Thank you for your time. David Leto