Queries on Japanese Mud Pond System (feeding regime, depth, condition...)

[dimashp]

Dear all,

I have a mud pond in Indonesia, its size is about 10m x 12.5m (it's not really a square pond, so it's a rough estimate), with a depth ranged from 0.8m to 1.4m. Water supply comes from spring water which is located just above it. pH ranges from 6.5-7.0 and gH is very low (i'm using Tetra gH Meter, and it shows that after the first drop, the colour changed), hence it is around 1. I can't find kH tester yet here.

The soil type is 'very very' muddy. After one month, the thickness of the mud reached 10-15. This is one of the main reason why its depth keeps decreasing.

The highest temperature is 27 C (during a very hot day) and the lowest is about 20 C (at night). My mud pond is located at the bottom of paddy field (maybe comparable to Japanese Mud Ponds).

My feeding regime is, currently, twice a day. Once at 8-10AM and in the afternoon around 4.30-5.30. I tried to feed them 3 times a day, at noon (12AM), but they seem reluctant to eat. Once a week, i feed them with vegetable (hmm...i have no idea what it is in English, Chye Sim-its green vegie though). One interesting thing is that there are plenty of small fresh water shrimps in the pond (this is may be one of the reason they refuse to eat at noon, they might eat these shrimps and other insects or other things). They love to go to the bank, and somekind like 'dig' the soil, i asked some of my friends, they say that they are actually considered as carp, hence, this is one of 'carp' syndrome (often, they are looking for worms and all).

I use it for the past one year, and i am quite satisfied with its performance. In fact, i put all my koi inside it for the whole year (since, my koi is still not even tosai, around 30cm when i put them inside). Most of them are locally bred and i had one Dainichi Showa last year, but it died which is my fault too, i did not quarantined her and i put her directly after she arrived in Indonesia (it's like 5 days frame...). Then, i was quite scared to buy another Japanese koi . However, i tried my luck again with another Ogon (Izumiya, if i'm not mistaken). Fortunately, she is okay now. and for updtae she grows about 6 cms in about 2 months time.

One of the growth rate sample, is my Bekko he was 28 cm last year, and now he is 45 cm. He is a male koi, and taking into consideration that he was one of my few experimental koi, he is locally bred with unknown parents. I bet his parents are all around 60cm.


There are some questions that i would like to ask you about mud pond system in Japan Basically, i want to compare the condition of mud pond that i have now and those at Japan. Although, the growth rate of my koi is considerably good (taking into consideration that most of them are locally bred with 'i have no idea what kind of oyagoi they used'), I believe there are other things that those mud ponds at Japan and (the system behind it). Pardon me, if my questions are too detailed and lenghty.

1. What's the maximum number of koi that my mud pond can hold to obtain maximum growth, do i need to deepen pond, if yes, how deep it should be ? (to make it easier, take average size of fish is about 50-60cm)

2. Once i heard that Oomo Mud Ponds are muddy too and it is desirable for rearing Showa, is it true ? if it is true is there analogy behind it ?

3. I've never been to Japan by myself, and from all mud pond photos that i've seen thru sites (Japan ones). I did not see any water input source, Is it true that mud ponds there do not have any 'input-output' water ?

4.This is my feeding regime( i've tried Nozomi, Hikari and now i'm using Ogata...All wheat germ...I've never feed any food enhancer for my koi) and i don't believe in spirulina until they really reach their peak...So far, Ogata gives the best result...Yet, what is Jap Farmer feeding regime (for their mud ponds) ?

5. Is it okay if those shrimps are there too ? and i've seen Sakai video that they do feed their koi wth vegetable ? Do vegetable has positive impact on koi ?

6. Is the growth rate of my Bekko considered good or bad ? Oh, he was taken into one koi show last year, so he was basically out for 3 weeks from the mud pond.

7. Lastly, this is maybe a stupid question...it is impossible to copy Jap Mud Ponds...yet...i just want to ask, what are other external things that Jap Farmer do to their mud ponds ( maybe something that is measurable e.q. they add some essence or something)



Well, i'm really sory if my questions are really long. I want to cull some of my koi and really concentrate on few but good koi-if that ogon is allright by the time i come back to Indonesia, i might start hunting some Jap Tosai.I'm a believer of nature law. I want to put them all inside mud pond until they reach Sansai and reach their peak and hopefully by the time, they are all stable. and by the time, i'll finish building my second concrete pond (around 150 tonnes). Hence, they can enjoy their new home.

I would really appreaciate if you could (or anyone) help me clarify my doubts.

Here i attached some views of my mud pond, and my Bekko sample from he was 28cm till that one is actually when he was 34 cm. My dad has not send my the latest photo to me yet.

Best Regards,


Dimas

[bekko]

Nice pond Dimas. I do not pretend to be in touch with mud pond management in Japan, but some things remain the same around the world. It would be hard to compare your pond to a koi mud pond in Japan though. The Japanese ponds are seasonally drained and dried. This, along with the colder winter temperatures, makes a big difference in how the pond behaves.

Is there is a lot of spring water running through your pond? A lot of water exchange in a mud pond is good and bad. It is good because it flushes away nutrients which helps prevent oxygen depletion. It is bad, because it flushes away nutrients and keeps natural productivity (development of natural food items) low. The best growth is usually in a pond with high natural productivity plus high oxygen from supplemental aeration.

If the water flow is not great, you should consider adding some agricultural lime to stabilize the pH. I would add 5 kg, check the pH after a week and add another 5 kg if it does not stay at 7.0 or above. Make sure is it agricultural lime (calcium carbonate), not quick lime (also called caustic lime, burnt lime, or calcium oxide).

The shrimp make great forage when the fish can catch them. If there are many koi, they will usually wipe out the shrimp. I doubt that seasonally-drained Japanese mud koi ponds ever have many shrimp. Chye sim and other leafy green vegetable are always good for koi. In a mud pond, the koi can often find other vegetable matter to eat. But, if they take the chye sim then it is good for them.

A muddy bottom is a nuisance when you need to work in the pond and it impacts water quality. 10 to 15 cm is not too bad though. The fish will root around in the bottom (like pigs) looking for food. When the fish disturb the bottom sediment, the sediment pulls oxygen out of the water above. The more organic matter there is in the sediment, the higher the oxygen demand. Bioturbation (fish rooting around in the mud) erodes the banks and keeps the bottom soft and muddy.

For get the maximum growth in a scavenger like koi/carp, the amount of fish should be less than about 1000 kilos per hectare. That would be only 12.5 kg in your pond, or about a half-dozen fish at 50-60 cm. However, you can get growth that is almost at it's maximum with two to three times that number. You could use the shrimp as a guide. When you have so many fish that the shrimp disappear, then you know you are not getting close to the maximum growth. Only you can decide which is more important - maximum growth or having a lot of fish.

I hate to keep harping about oxygen, but that is always the first thing to become a problem when you increase the number of fish and amount of feed in a mud pond. If electricity is available, aeration is the best thing you could do for your pond and your fish. If supplemental aeration is not possible, then try to keep the feed rate below 350 grams (dry weight) per day. 350 grams per day can maintain about a dozen fish.

-steve

[dimashp]

Dear Steve,

Thank you so much for your input !

For rate of flow of water, i am not sure wether it is considered too fast or too slow. The only thing i can measure is that, it comes from 2.5 inches pipe, which has quite high rate (again, i cant get the exact value in dV/dt hahaha...but it took about 6 hours or more to fill the pond from zero). Yet, what i can conclude is that, i do not think that there's oxygen level problem for my pond. There's no sign of it and no sign of any weed or green water yet. I believe this because, before the water enters the pond, it actually pass thru a small (i have no idea what to call this in english) 'bank' beside the paddy field on top, and there are huge surface area and volime ration, and with lots of small rapids to increase oxygen concentration.

To tell you the truth, there are about 14 fishes there (most of them 40-50cm now) and from those 14...I only want to keep 3+1+3...3 koi which are considered show quality, 1 which is very interesting kohaku, which i want to see him in his 60-70cm since it has a unique skin-it glitters like ginrin, but it is not ginrin...and 3 which are the first 3 koi i purchased before i become 'full time' koi addict...but then, those 3 koi i'll put inside my current concrete pond.......so there will be at most 4 koi for now...

and if in this case only 4 koi, sized 40+cm...how should my feeding regime goes ? is it still 350g a day ? anyway, 350g a day means every one feeding time or 350g is a total a day ?

Thanks alot !

Dimas

[bekko]

Oh, that's a LOT of water Dimas - 400% exchange per day. Forget everything I said above as almost nothing applies at that flow rate. What does the drain pipe look like?

-steve

[wibowo]

wow, nice pond dimas, can i "titip" 1 of my kohaku into your pond .
she has nice pattern ( 4 step maruten ) n skin quality but too coward to compete with the other koi for food, as a result she did not grow very well compare to other .
it's a shame coz in my opinion she has the potential to be show koi in the future .

[dimashp]

dear all,

steve :

hmm...that happens during rainy season where water is really abundant, during hot season (like now) it took slightly longer about 8 hours, anyway, still lot of water i guess...haha...

about the draining, i'm using pre-historical system (hehe...), it has two water input, one is the one connected directly into the spring up there, the other one, connected to other spring but a smaller scale...and the output, it is just a pipe at the other side of the pond, which is set up at the maximum level of the pond ( what i mean, i have about 20cm benchmark, for the water level so that it won't get flooded in )...so it is just simply in and out...maybe, you'll worry about the nitrate level and sediments inside it...but maybe this one is kinda belief 'of nature law' since, there may be some good bactriam or anything like that to degrade the bad substances...hehe...

and...how about the feeding rate ? is 350g is per day ? or per one feeding time ?

wibowo :

thanks for your compliment...my pleasure to have it !!! but since i'm in Singapore now and only be back to Indonesia mid May, maybe we could discuss about it later once i come back, i'll be doing major pond upgrade once i come back, and i'll cull or sell koi that i don't want...then here you go...

Regards,

Dimas

[bekko]

Quote: how about the feeding rate ? is 350g is per day ? or per one feeding time ?

You do not need to worry about that with 3-4 water exchanges per day.

I asked abot the drain because with that much water flow, you could use the water flow to help remove some of the mud and sludge from the bottom of the pond. You would need to put a tee fitting (not an el fitting because it could start a siphon) on the drain pipe at the water level and run a large piece of hose down to the bottom. If it is flexable hose, you can move it around every day or so to pull mud from a different area of the pond. Probably would not work if the pipe is more than about 15 cm. Something like this....


-steve

[dimashp]

Dear Bekko,

Thanks for your idea man ! I just realised that physics can be applied here too ! Anyway, after talking with my parents, they are agreed to renovate my mud pond, and a hint of possible extension...so i guess, i will keep in touch with you if i have any doubts and queries, hope you don't mind =D

Thanks alot !

Dimas