My 55 has had a Whisper 60 and a TetraTec PF300 as its filters for many years. I love how quiet the Whisper 60 is but the TetraTec is so loud I can hear it from almost anywhere in the house. My wife has finally given me the ok to replace it so, what do you recommend? If I get another Whisper 60, I can just take the filter media out of the TetraTec and put it in the new 60. But, if there is another filter out there that is as quiet as the 60 but better, I want to at least consider it. I am looking to stay under the $30 mark as the 60 is $27.