A couple of pond questions.

[classic-chassis]

I'm moving house, the new house has a pond. It's about two and a half meters by 2 meters square. I'm not sure how deep it is. The previous owner kept koi carp in it so i'm really exited about becoming a pond keeper.
It has what i presume is a canister filter. They make them out of plastic drums here, i think it's a 20 gal drum. the drum is plumbed in with an in and outlet so i presume this canister works like a canister for a fish tank. It that correct?
sorry i don't have photos yet.

The pond has been sat for a long time with water in it, so i'm thinking i will need to drain it, clean all the crap out and refill it. Will i need to cycle the pond as one would with a big fish tank?
It also has a Thai style statue which is also a fountain in it.

I do keep a 200 gal fish tank, so i'm not a true noob, but i've never kept a pond before.

 

[bomber]

What I did for my outdoor pond was seed all my bio media in an established monster tank.

Test the pond parameters like you would your fish tank and you should be right on track.

When in doubt, test your water.

 

[classic-chassis]

The water in it now is close to stagnant. There are a lot of dead leaves from a mango tree that it sits under, probably a few rotten mangos in there as well. I think draining it and starting fresh will be the best option.
As for seeding media, if i put the new media in my sump of the big tank, how long before it's seeded?

 

[Muske]

If there is leaves and other debris in it, def. drain it.

I wouldn't totally scrub the interior of the pond though. Some of the bio-film on the walls and statue will help re-establish some of the good bacteria.

A few weeks of media in a sump should be long enough for it to get seeded. When you set-up the new pond, squeeze out media from your tank into the filter and/or pond from your tank.

Check to make sure water temps. are close to each other when swapping media.