Fish Pond or No Fishpond?

Any advice from fish pond owners gratefully received.
When we moved we brought our 4 goldfish (18cm length now) with us (why wouldn't you?). they are living in a 1600lt trough which has a homemade biological filter and a 6000lt per hour pump. The pond is in an out of the way place (convenient to power) so only gets visited occasionally. It is covered with shade cloth so hasn't gone green yet!
I would love to have it nearer the house but this involves getting power put on and doing some landscaping. This is all OK if it doesn't turn into pea soup. Anyone out there have a clear pond all year round and how do they achieve It?
Thanks

Solar powered pump.

Hi, have looked into solar but they don't produce enough power to cycle the volume of water required and of course no pump at night unless I install batteries.

I bought a place with a fish pond, 5 large goldfish included. No pump, not much to it, concrete bottom, a few meters across, a wire net to exclude birds that might want to snack on the fish. I do almost nothing to it...if the water gets low, I add water. It's under an apple tree and I've had to get dropped fruit off the screen. Quite a few snails live in the pond, lots of much on the bottom, it's a bit of a miniature ecosystem. I don't feed the fish. They're doing fine. The people I bought from said they didn't even know there were fish there until they cut back overgrown vegetation
...so I'd say the fish have thrived on neglect for at least a decade. I did hear a report that some kids stole a few fish at one point. Bottom line...there may be no need to get fancy.

Thanks. Have done a bit more research and looks like I can filter the water through a bog garden which should give a nice clear pond with no need for expensive UV filters. The trick is getting the eco system balanced and reducing too much light.