What is the optimum shape of a koi pond?

[kiky]

I agree with Luke. Currently I myself am constructing a pond 4m x 7m and 2.75m deep. If not for space problem, maybe I'll make it at least

10m long.

However, from personnal observation at fellow hobbyists's ponds in my area, I noticed that circular ponds with visibly strong circular current results in faster grow. Is this a co-incidence or is there some explanation?

[Lee]

Dear Friends,



One can near fall off a chair in laughter in this delightful interchange of ideas.



Agreed. An elongated egg shape>Yes, I too believe is the very best.



It is the best shape as it encourages the same movement as the vortex, dragging the "poop' down towards the bottom drain, giving easiest flow and movement to the pond water and the best exercise possible to our koi.



Why then are the Japanese offering the rectangular shape as the best?



For certain, they don't believe, nor do I, that our koi will become bent in one direction if they're required to only swim in against the same current all of their lives...



My koi appear to race round and around and across and back and forth, they've no set pattern and this is after moving all water flow in a clock wise direction.



Do we have enough who agree to the above? Or, are there others with an entirely different opinion?



Lee

Grand Cayman

[Mike Mazur]

heres one to rool ya onto the floor. Lee you being kinda close to the equator needn't pond_er this... Up her above the equator our water going down a drain will spin in a clockwise fashion where it will do the opposite in the southern hemisphere. to emulate nature in the northern hemisphere then we should spin the pond in a clockwise fashion and vice versa the other side of the world. near the eqator supposedly the water will impart no spin on its own so choice is yours. just another bit to chuckle about. Mike

[MikeM]

Lee: I'd agree on the elongated oval idea as accomodating movement of the fish and encouraging exercise w/o injury, but that does not necessarily mean one goes for the circular water movement of the British system. :wink: However, I have to say that the availability of top quality filtration devices geared to the British system makes it much easier to adopt.... at least for those of us in the West. I like the straight water flow of the endless system due to the naturalness of the look. But, I have not found the sort of detail on making it work as can be found on the British system. Also, keep in mind that it is not uncommon for substantial in-flows of fresh water to be used in Japanese systems, so they do not have to address some of the water quality concerns a fully closed system must address. Have to understand it all before can really decide, and I'm not there in my knowledge curve.

[Lee]

Dear Mike and other posters...



If we seriously consider Mike's 'tongue in cheek' post about where on this planet we dig our optimum shaped koi pond - then indeed, there may be merit to the endless pond rectangular pond shape -



If at the equator the water neither flows clockwise or counter-clockwise then it must flow 'endlessly'...



Excuse me, Mike...whilst I go and have a shot of scotch.



Yes, Mike...you're indeed, the type of koi ponder that we all are...you're just a bit more up-front, is all.



Thus, even if NONE of you are deemed satisfied by this thread, I will 'now' tend to be comfortable come Boxing Day - when the excavation company I hired earlier today arrives and begins to 'dig' my new pond.



...which shape, is an exaggerated 'egg' shape!



Lee

Grand Cayman

[MCA]

Howdy Lee,



How do we metric "best"? Is it based on water quality parameters (as much to do with the filters as the pond shape/size. Or is it the number of koi that can be kept (regardless of size) or the number of potential GCs that can be grown on or... or one dear to my heart.... the largest volume to fit into the available space...



I go for the rounded off rectangle. I have yet to see/hear anything substantial on the benefits or a egg shape. I doubt it is on the top in terms of real estate usage. But that may not be the desired metric.



MCA

[Lee]

Michael,



I think the determining factor for your choice of 'new' pond was your previous pond's shape. It is my belief that often we again do what we had before, as we were comfortable with what he had, as well as, we understood it's construction. And thus...we do it again.



In regard to shape. I know that you preferentially choose a Nexus rather than a box filter. I belive if you examine the shape of the Nexus, it will be round and have the same charterisitics of shape and volumn as is prescribed by the rounded or egg shaped pond that is 'what I suggest' is the optimum shape.



If the Nexus was rectangular shaped with rounded corners and you had opted to purchase a filter system of this shape, I would have readily agreed...however, you did not choose a rectangular shaped filter, so whether you admit it or not, I say, you prefer the round shape, as it is more efficient (in filtering your pond water) than a rectangular shape.



And, somehow it fit...into your yard, also.



The above conclusion suggests that you need start all over again and rid your self of the classic rectangular shape and go 'round'...and, round.



Warmest holiday greetings to my dearest friends...



Your pal



Lee

Grand Cayman

[MCA]

Lee,



Round ponds have definite size limit. For example. with my 10x16 shape I get 158 square feet of surface (160 minus 2 for the rounded corners). To get something in that range, the round pound would need to be around 14' in diameter (7x7=49 x 3.14 = 153.86 square feet). Increasing the diameter to 14.5' gives a surface area of 176.625 square feet. I just can't see neting in such a big circle. Also the larger the circle the less useful a seine net would be (compared to being just as useful in a large oval or rectangular pond).



Another aspect of a round pond is the use of bottom drains. With a round pond the logical location of single bottom drain would be dead center at the bottom. But with 4" pipe you can only do around 3,000 gph with a gravity feed filter system. Even allowing an equal volume of water going through a skimmer or mid-water pickup, I still would not want that low a percentage off the bottom. So for a really large round pond do you do a cluster of 2-4 bottom drains beside each other? Something to consider....



I think the largest round pond I would try would be in the 12' range.





MCA

[Mike Mazur]

think of how much easier a time MCA's avatar would have if at least the corners were rounded. LOL couldn't resist now that this thread is nearing end? lets think of this koi pond or lake? those of us emulating nature having a pond is simple to make a lake you need that flow through by definition so if you go with a flow through endless design ya better build BIG!

[markgardner]

I think the reality of why ponds are rectangular is simply for no other reason than that they maximise the use of available space.



As long as the chosen design allows good water movement, doesn't contain areas to trap crap (i.e. no intricate little nooks and crannies) and is of sufficient size and depth then i'm inclined to suggest the specific shape is largely irrelevant.