Reduced flow rate at night ?

[Lau Teck Seng]

Hi all ,

Would it be a good idea to reduce the turbulence in the pond by reducing pump flow rate at night ? I understand that kois are pond fish not fast water fish like salmon etc. So it would be good idea to reduce the water flow into the pond , or at least cut mid water , bottom push pumps at night so that the kois can rest better ? I have a 60 tonne pond serviced by 5 tsurumi pump (12-15 ton per hrs each) for 2 mid water , 1 bottom push , 2 top water venturis and 2 water fall.

Your feedback is very appreciated and thanks

ts

[PapaBear]

Yes and No.
Koi are only pond fish because we keep them there. They are really "riverine" carp, which do well with currents. That being said, they do need a resting time/place. Not knowing the way water moves in your pond makes it difficult to say what is best, but if they really don't have a place to relax your idea of changing the mid water returns at night might be good.

[MikeM]

In every pond I have seen, there are quiet areas where the koi gather when resting. Your pond may be different, but I doubt it.

BTW, if you do alter the currents, you should do it consistently... every evening. Koi do not like changes in their environment. They will be disturbed by the change at first. Once they learn that it happens every day at the same time, or as it gets dark, they will adjust. Changing the currents only sometimes and at different times (especially in relation to the light)will be very disturbing to the koi, increasing the release of the 'fear hormones', etc. Regularity and consistency are important in most things koi.

[koibooi]

I have two bottom drains that feed 120 liters per minute through my 30 ton pond for 24 hours a day. A friend of mine has a similar setup except that his bottom drain air pump is on a timer and switches off at night. I have not seen any benefits or disadvantages from either approach. My argument is that lots of air is great. His argument is that the Koi need some sleep/quite time and the constant droning of the air does not give it to them. Comments ?????

[schildkoi]

As Papabear mentioned, Koi are simply inbred riverine carp. They do not need "still" water to rest nor should the constant hum of an airpump/airflow have any detrimental effects since sound waves in water travel very easily and if one thinks about a river, or even a lake, their are also noises. A koi will rest nicely in curents of 9in/sec and gently drift. Although a diffuser dome will create large currents and water flow, the exponentially decrease with distance from such.

Steve

[Lau Teck Seng]

The pond is rectangular , 26ft with rounded corners . Flows are anticlock wise and pretty fast judging from the way the kois wim against the current .And also the spiralling and dancing air bubbles as they flow to surface. Three bottom drain at centre , where its pretty slow but with two waterfall and air domes running here. Another slow area is the corner just before all the pump outlet , but there is 2 hiblow 150 equivalent running airtubes.
So not much resting areas for 25 kois ranging from 30 to 75cm. Am planning to put one pump maybe 2 running the bottom push and mid water on timer . So when lights out , pumps out as well. What are your thoughts ?

Mike , never thought of the stress factor . Think like a koi , maybe was a koi in past life ?

thanks
ts