A few basic koi pond questions

[sick_lid]

I'm still sifting through posts on here to get some more info, but wanted to open this for extra help. Even pointing me to where the answers are would be super helpful too.

So right now I have 10 koi/butterfly koi (1.5") I am growing out in a 75 with a larger pleco. My plans are to build a small outdoor pond maybe 2-300 gallons to put maybe 7 or 8 of the koi and the pleco in when they get about 6" or so.

Whether i dig a hole and run liner, or build up a wooden box with a liner, my main questions are filtration. I've got a model 7 utility pump from an old sump setup I was planning on rigging up into a waterfall for some surface agitation, but what else is needed for filtration on a small project like this?

As far as water changes, how important are they on ponds? Is it done by just pumping it out with the pump, cause I don't see a siphon working.. Substrate cleaning?

I've been a fish keeper for many years with large tanks and many different species, but this is my first time venturing into a pond, and koi as well. Anything helps really, as I still have many months to learn and prepare as these youngsters put some growth on. Thanks all!

Edit : Also, I am aware of the sizes these fish reach, and the pond in topic will not be a "for life" type of deal. I am not wanting to throw a handful of 6" koi into a 1000 plus gallon pond - if we enjoy the experience and decide to keep and make this a for life project, it can definitely be done. Thanks again.

 

[hankn]

I've got a model 7 utility pump from an old sump setup I was planning on rigging up into a waterfall for some surface agitation, but what else is needed for filtration on a small project like this?

As far as water changes, how important are they on ponds? Is it done by just pumping it out with the pump, cause I don't see a siphon working.. Substrate cleaning?

1. www.interall.co.il/filter.html

2. The first year I did water changes but now in my 4th year I do not do any water changes. I add 5-10cm of water per week due to evaporation and add a drop of Prime but no water changes. Water quality is excellent.

3. After 3 years of having smooth river rocks at the bottom of the pond and having to clean out the substrate every spring, I decided this year to remove all those rocks and the pond runs cleaner since gunk doesn't get caught in the substrate and gets pulled to the pump and out to the filter. So I would recommend against putting in any substrate.

 

[Muske]

5 years with gravel on the bottom and rocks/boulders along the shelves. No problems ever with water quality issues. It comes down to personal preference.

I do a 20-30% water change in fall and spring to dillute any extra nutrients. It helps compensate for lack of nutrient uptake by the plants.
No other water change during the season, just top off.
You might need to do small, more regular, WC's with a pond in the 2-300 gal. range and growing Koi.

You might be able to run a small skippy filter on a Mag 7. You can then upgrade with filter, pump and pond.