Question
I have a Koi pond that was built for me by a local contractor who had little experiance with Koi ponds. The design includes a waterfall. The pump he used is driven by a 3/4 HP 220V motor which makes a lot of noise. My neighbor complained to the city and the Code Enforfement department determined that the sound level exceeded the permissable limit. I tried building a wodden box over it but it overheated and shut down. I would like information on how to redesign the pump/filter system to be as quiet as possible.

Answer
Hi Rick,
I would suggest you either change your pump maybe for two smaller and quieter ones to give the same flow rate or,use a submersible pump you cannot hear them.
You can visit my pond and filter system on my website at http://koi-z-are-us.20m.com
George.