ferrara said:
Ok Rough messurment for the pond is
Length 9ft
Width 5ft
Depth 1ft
Wow, are you sure its only 1 foot deep? That's really shallow, I don't know how it would keep from freezing in the Winter.
Well, going by those dimensions, you are looking at around 330 gallons for your pond. Personally, I think your pump and filter are terribly under-rated for that size of pond, but I'm sure others will chime in. Koi will put out more waste than regular goldfish, and I'm a firm believer in over-filtration. I sized my biofilter to be about 10% the size of my pond. Of course you may not have the time to build a new pump and filter system, but I would keep it in mind as a long-term option because it will improve the health of your fish and require less maintenance.
I was out shopping today for weatherproof outlets, and I found some similar
to this one. You can get single or double outlet boxes, and the cord runs out the bottom to keep water out. I had originally planned on cutting the plug on my pumps and direct-wiring them, but seeing this, I think I will leave the plugs intact so that I can move the water pumps if needed.