Pond length and body development

[hwong]

How true is it that a koi's body will develop unevenly on one side if the pond is short and the koi has to keep circling. If a koi has developed a"deformity" due to this ueneven growth, can a period in a long pond or mud pond correct this deformity? I attach a pic of my Showa that has this problem. I have a couple of others that started out straight but will develop an indentation on its left side just like the showa.

Will appreciate your comments on your own experience.

[soelistyo]

Hwong, i have a 91cm soragoi that started to have the same problem when it hit 80cm. a few dealers told me it's because my pond is too small (4.4m x 2.2m) for it to have the required exercise.
does your water circulate in a particular direction? i was advised to reverse this circulation direction every month, that might help somewhat. unfortunately for me, my pond set up doesn't allow for that.
i believe female koi are more susceptible to this problem?
i've seen your pond and i recall it's pretty large, way larger than mine, though more squarish in shape. hope to see you receive good advice here, could be of help to me too.

[dick benbow]

The problem is a difficult one. It has to do with excercise and the koi's ability to do some lengthy runs against current. Most of us don't have ponds long enough. But reverse current is a good idea. If it took several years for this condition. i would think it would be the same amount would hold true to undo it. Verypretty koi!

[luke frisbee]

Something for you to consider...
An Ice eater from Power House inc.

When i was playing with the 1.5 amp model in my 18ft x 4.5 ft by 6ft deep QT it would get the whole thing moving with a good current. in 1 minute. I used to leave it on for a couple of hours a day but then I found a couple of dead fish and a couple more with "whacks" on them. I guess they got used to the thing being on and didn't stay away from the propeller.
I'll build a cage and use it again....once I get done with Lake Luke

[bekko]

That fish almost looks like a female with one impacted ovary and one spent ovary.

-steve hopkins

[marco]

Hwong,

I had the same idea then Steve, and the only way to know it is to make an echography. .. I'm not jocking, I did it on mine just to see if it was possible to make the difference between male and female. The ovary can be seen easly but it was not possible to do the difference between male and female because the brillance of ovary and testicules are the same.
You just have to find a person who has an portable echography ....

[hwong]

Hi Fellas, thks for the feedback. My water used to return via venturis that runs anticlockwise. The kois happen to swim anticlockwise too. When I observed the deformity, I removed the venturis. The kois are still swimming anti clockwise. One koi that was introduced after the venturis were removed also developed this indentation on the right side. I checked with DTBH who had alternated the flow direction in his pond. He says his kois doesnt change direction to swim against the current.

My Pond is only 16X11.5X5ft. so a flick of the tail and the koi reaches the end of the pond and have to steer left.

Meanwhile I have sent one koi to the mud pond for a 6 months vacation and I will know in 4 months time if there is any improvement.

Rgding egg impaction, I have tried unsuccessfully to make her spawn . I will give it another go this weekend.

Pls keep the discussion going as I believe, this may be a common problem.

[Akai-San]

Interesting discussion. While designing pond, I had the same concern regarding currents in the pond. I guess my problem was having a long narrow pond, 10'x30'x6' deep. The design would instill a clockwise current within the pond aided by interior water jets (like swimming pools) to eliminate dead spots and move debri to the center bottom drains. With this discussion of koi bodies going lop sided do to current regularity, this concerns me.

Instead of circular currents, how about linear currents through the pond? Run all returning water and interior jets towards one side of the pond and exit water at higher rate at other end of the pond (just like a flowing river).

[luke frisbee]

Akai. My 3000 gallon QT is one direction flow. it does ok. No real strong flow though...until i turn onthe ice eater.

[bekko]

That one-direction-flow stuff does not work that way. If it did, then in a 30 foot long pond with a pump turning the water over in one hour, the maximum velocity would be 0.5 ft/min - really slow. In practice, there are high velocity areas near the return lines where the flow is about 500 to 1000 ft/min There will also be large turbulent areas. Finally, there will be eddies where water flows in the opposite direction and back towards the return outlet.

One thing about orienting the returns in such as way as to make a clockwise or counterclockwise gyre is that the flow is predictable. You know that the maximum velocity will be near the pond perimeter and the lowest velocity will be in the center (not counting the zero-velocity film on the hard surfaces). This provides some assurance that the deposition (sedimentation) zone will be in the center where your bottom drains are.

If the returns are all pointed towards the same wall, then you cannot easily predict where the deposition zone(s) will be and the location of the deposition zone(s) can shift dramatically with just a minor change in the orientation of the return lines.

I do not know what is best for the koi's swimming behavior. My fish do not seem to pay any attention to the flow direction and just sort of meander around.