Noisy Aquaone Cf-1000

[chemflex]

All I can hear is the constant movement of the bio balls in my CF1000 filter. Is this normal? - surely not! If there anything I can do to stop it?

 

[billybean]

All I can hear is the constant movement of the bio balls in my CF1000 filter. Is this normal? - surely not! If there anything I can do to stop it?

me 2 guy at the fish shop said 2 wrap filter wool around them, i,m a newbie tho r u supposed 2 put them in the filter trays or at the very bottom, this is where they sound the loudest /