Does it seem like it's flowing less than it was previously, or is this new to you? My 305 doesn't have much flow. So if it's new to you, that may be why. If it's lower than it has been, check and make sure that you don't have air in it. Also, make sure your impeller and housing are clean. Check that your sponges and other media are farily clean. You can turn off the flow on the valve, remove the hoses, hold them over a bucket, and 'flush' them as well (make sure inlet and outlet are below water when you do it.)... that should show whether the hoses may be clogged.
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