Hi, new to koi keeping

[Hobolarry]

Hi im Hadyn. we finished our pond a few months ago and until the other day only had about 10 goldfish in it. we travelled down to weston super mare to collect some fish(we live in gloucestershire) and ended up with about 10 14-18" ghost koi and various other goldfish and orfe. we have never really had koi before and we have been offered some more. I know opinions obviously differ on the subject of care but just looking for some advice. The pond is 30x12m and is about 1.5ish m in the deepest part I think after using an internet calculator that its about 55000 gallons although i may be wrong.do koi HAVE to have filtration or can you just have a well balanced ecosystem eg plants etc. we are planning to put a waterfall in which will filter a little and aerate. but will the plants keep the water good enough by themselves? also would koi be fine being left outside all year round? I think that is enough questions for now .
many thanks
Hadyn Townley

[site admin]

Hi Hadyn,
Welcome to the forum, that is certainly a large pond.
I would think that if it was well planted with oxygenating plants and also include some more air difusers, and once mature there would be no need for extra filtration. I think adding some clay would help to mineralise the water.The waterfall would be a good idea.
The koi would be OK in that depth through the Winter.
Hope it helps,

Would be nice to see some photo's.
regards
Dave.

[roselanekoi]

Hi Hadyn,

That's not a pond its a lake.

As Dave has said you do not have to have a filter and can rely on mother nature to provide the filtration. Until all your plants are established I would refrain from adding any more fish.

One problem you are certainly going to have as the weather warms up is green water which will probably persist until your plants become established. This will not harm the fish it just means you can't see them very well.

The other requirement is going to be aeration for the water in the warmer weather which your waterfall should provide,

Regards,

Colin

[Hobolarry]

i hope that works that is a picture of the shallower end is is less than a quarter of the overall surface area of the pond. To give you a better idea of size the white fish in the foreground is about a foot long. sorry its not the best picture im at uni still at the moment so dont have access to the pond itself! will be home soonish though and will take a better picture then
Hadyn