Originally Posted by J.Mcpeak
Tip filter to ensure it has no air trapped within, this can make them noisy.
(Tip slightly left so the outflow is uppermost, if air bubbles come out that's it, then sit filter back down to normal position)
Hopefully that should fix the issue?
I agree to check for air. Most likely culprit of newly set up canisters. Especially fluval.
When everything is running normal the filter will hum slightly, they are never really 'Silent'
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