Koi-Food

[Mike Snaden]

Well, I'm working on it! Plenty of aeration to keep me excercising

[B.Scott]

Bubbles in your pint don't count as aeration Mike.

[ranskye]

hello i am new here, i came here to find what you people feed koi fry.
i operate a fish farm of 20 hectares and recently have been granted license to run koi and goldfish.
i have been producing fish for 5 years. koi for 3. still i have problems that are through lack of knowledge or time spent working with them.
i am guessing that the correlation between a certain koi feed and the contraction of disease is that if the carp pox is existing withing the pond then yes the fish that are fed a poor diet are susceptible.
however some diseases will attack regardless. there is differentiation between such diseases of which i am unsure which carp pox falls under, though it is best to be safe and have good water and good feeding and handling practises.
if water quality is poor and diet and handling is poor then diease will likely occur.
it may be that people that feed poorly will also likely have poor water quality through lack of knowledge or lack of time spent due to not being mad in the mind with humanXfish blood running ever present through the brain!
we are all here for a reason.. we must remember to eat well ourselves or our health may suffer also.

[bekko]

True fry will do best with abundant zooplankton and infusoria. When supplemental (dry or paste) feed is used to boost the bulk calories, the quality of the dry feed is much less important if the fry are getting all the essential nutrients from natural forage. As fish biomass (density) increases and the contribution of natural productivity decreases, the quality of the dry or paste feed must be increased.

Maybe Bill, the nutritionist, will step up here. However, without knowing what feeds and/or feed ingredients you have at your disposal, it will be hard to suggest a formulation. In general, you may want lower protein and higher carbohydrates than what is used for many other species.

Like you, I suspect most diseases are more likely to erupt if there is poor water quality or poor diet. Carp pox is a virus which a healthy koi can apparently be exposed to without becoming diseased. But, I am not sure if that is the case for koi herpes virus (KHV) and spring viraemia of carp (SVC). You are probably taking precautions to insure that KHV does not enter your facility.

Where are you ranskye?

-steve hopkins

[ranskye]

hi steve,
i am in australia, i will be using a standard silver perch fertilisation regime to get a bloom up in my ponds.
this would consist of bales of hay, cottonseed meal and pollard for the organic side of things and di ammonia phos, urea and potash for inorganic.
this should do a good job at producing the live feed for the koi. it does the trick for the natives round here..
i worked at a farm once where we had one meg concrete tanks and we did koi and goldfish and they used to feed them a slurry of powdered fish pellets (ground up to less than 1mm, we also tried a high protien barramundi diet, which seemed to do better than the carbo one but maybe the carbo one was poor in other things..
thing was i reckon the only live feed was in small amounts as we never fertilised there and hardly had green water as such, we had no aeration and we would get a die off of maybe 20 percent as the biomass increased. the only fert was what was left in the pond from the previous crop. fish crap.
so this time i want to have more live food and earation.
as well as this we used to spawn in the pond and remove parents and sometimes we would have large numbers of eggs that were attacked by fungus, i wasnt sure if this was due to infertile eggs due to the milt drifting off or temperatures or what but it seemed to be related to temp. i figure this time round i could spawn in a hatchery tank and release the fry into the pond at 2 days after hatch.
we used to get about a hundred thousand from a pond but many would be eaten by the bargers, sometimes wed harvest 20,000 only.
i remember one time we spawned these goldfish and we had a unusually high
hatch out, so many hundreds of thousands that we couldnt keep em fed and it turned out to be a bad crop. funny thing was the only differerence was that we had filled this big hole in the pond bottom with river sand so maybe the eggs sunk and hit the sand and lived instead of dying on the bottom. this is why i want to spawn in tanks now where i can keep an eye out and maintain less broodstock that are better quality. wish i could get some big fat stock from japan actually..
i was wondering if i should start feeding in the hatchery tanks before dropping them into the big ponds but it seems like a lot of trouble if the little fry will get the best nutrition in a pond anyway..
thanks bloke.

[bekko]

Maybe Maurice will jump in here, because I remember him doing some intensive larval rearing. I have to use quasi-intensive larval rearing because I'm so cramped for space. My preference would be to spread the fry out in large enough ponds that they did not need anything except natural forage until they are 4-6 cm and large enough to harvest.

Since I have to augment the fry's food to compensate for the lack of space I designate a couple of units as plankton reactors. There needs to be a green water reactor. This is often a unit with slightly older fish which are being fed dry feed. They will keep the zooplankton stripped out of the water because of the intense competition so the green water gets really dense and stable. I continually siphon water from the green water pond to a zooplankton unit which has a good bloom of rotifers, Moina (a large Cladoceran) or copepods. If the flow rate of green water to the zooplankton pond is right, the zooplankton density stays pretty high - several hundred rotifers/ml or 20-50 Moina/ml or 10-20 copepods/ml. Water is continually siphoned from the zooplankton unit to the fry units(s) where it is stripped away by the fry. Using a small submersible pump with fine screen on the suction (a "bongo" set-up, if you know that term) water is continually pumped from the fry unit back to the green water unit. So, it makes a loop: green water --> zooplankton --> fry --> green water. Since the units are all at the same elevation and the flow rates are low, the difference in water level between units is very small. Getting the correct flow rate is critical so as not to "wash out" the zooplankton unit while providing maximum forage to the fry. The pump could be placed in any of the three units, but I suspend the pump just under the water surface in the fry unit. This way, if the suction screen clogs or a siphon breaks overnight, the pond can will only be pumped down a couple of cm before everything stops.

I also start supplementing with dry food as soon as possible. Last year, I used dry shrimp larvae feeds made by Zeigler. There are different size grades (<100 micron, 100-150 micron, 150-250, 250-450). The particles stay suspended and intact longer than something I would grind myself. They also mill the ingredients very fine so each particle has the same mix of ingredients. Shrimp feed was what I could get quickly (poor planning on my part) but Inve and others also have some fish larvae feeds developed for seabass and such. Don't they have some good barramundi larval diets? I plan to also use a little frozen Cyclopeze starting about day 12 this year. It's frozen copepods from an arctic lake or something (google it). This is, without doubt, the best off-the-shelf food for small fish I have ever come across. It's really expensive, but may actually produce results as good as having higher concentrations of natural forage.

I know growth and survival is correlated with the amount of live forage available. I also see some circumstantial evidence that some of the common deformities are less prevalent in batches with more live forage. In particular, I suspect that the flared gill deformity is related to a nutritional deficiency.

If you are going to augment the zooplankton (as discussed above) or do supplemental feeding, good aeration is essential. Both of these activities have a BOD which will crash the system if there is not enough aeration. I used to borrow a dissolved oxygen meter when needed but finally bought one last year. Some aerated fry ponds were found to have pretty marginal D.O. at times so I'm increasing the aeration for this year.

Koi people always advise against using too rich a diet. It is not surprising to hear that you get better results with a high protein diet for fry though. The shrimp feed mentioned is up there about 45-50% (do not have the can in front of me). I think the high carb thing comes into play later.

-steve hopkins

[ranskye]

good letter steve, much useful information.
and a man with a DO meter..go go steve.
i knew a guy with perch in a pond and one had 0 reading the other 0 and the one that had zero and an earator survived while the other died out.
seems they were trailing in the wake of the aerator and handled it.

i see what you mean by being cramped for space and having to go to the extra effort in providing feeding.
i understand your bongo pump thingy, i have heard of a way to produce god densities of rotifers through a tank with constant feeding of algae, yours is much the same and rather clever. they use a dose peristaltic pump to administer algae i think in the form of alga tablets. they use a drum filter to harvest the rotifers out and leave some in to continue the cycle, once again expensive to keep an eye on and to feed with the purchased alga tablets.
thoguh in a small tank i think primary nutrients are lacking and the boosting is neccessary and a bugger.. nothing like a pond full of calcium and micronutrients and all the other goodies that nature provides. seleniums and silicons.. the periodic table holds more than a bottle of fertiliser does..like a glass of water only has what you put in so so does any intensive produced food sources..
apart from hatching brine shrimp as a first feed, i have only ever created a bloom in a pond and used that as a holding rearing pond and yes the food runs out somedeay but with koi they wean easy as compared to our native fresh and marines.. ive seen em picking at food particles at about 3 days old but yes id rather them eat live stuuf anyday whilst young.
i saw once that gill problem in goldfish and thought it was a lack of oxygen or crowding at the time but yes this couldve been lack of oxygen=crash=lack of good nutrition for sure. feeders.

i read about some chinese guy working on rotifers and the like, (yes i have copepods too, geez theyre really supplying the goods now arent they!.)
he was into running highly fertilised algae ponds then pumping (i can drain due to my topography) the green water to his rotifer ponds then harvesting them and feeding to another pond with fry to fingerlings.
seems your trip is the same on a small scale but continuous.
i like this idea as the fish arent living in the high fertiliser and swinging parameter water,that the algae can tolerate. it was found that rotifers can tolerate really high levels and it hindered other unwanted zooplanktons. im thinking i can set it up almost automatic like your system.
in that i cna harvest rotifers and copepods with the use of fine mesh circle nets and automatic gate valves that open up with a 12v battery to drain away to pond once trapped.

i have checked out the inve and other things and yes those shrimp diets seem good in that they dont break down easy, the micro diets would be good though costly.

so for me its to trying the three stage idea. with just hatching them and releasing them. dropping the algae to rotifer copepods then after that supplementing them commercial ground pellet feed.

i know most hate the idea of a high protien diet for koi!
yes they dont have teeth. they dont have a predator gut but one that absorbs carbs and other organic plant type matter and that but while young they are predator feeders eating protien rich zooplanktons..

do you know of a way how to get a better hatch out, like what do you guys use apart from malachite?? salt? ive heard that if you use salt at 3 ppt the eggs begin to lose theyre stick and i can bubble them up in a hatching tank as i do now with other fish.
any ideas on the best easiest way? even when i have clean water thats 20 degrees i get a great number that fungus, is this cause theyre not viable to begin with or fungus attacking a viable egg? would you use UV if this be the case or salt?

ok must go check on my koi that got stuck in the egg netting. must change that too.
thanks again for feedback.

[bekko]

A lot of guys here swear by heavily stocked and fed tilapia ponds/tanks for making green water. The dogma is that the tilapia strain stuff through their gill rakers and, in doing, remove everything but small single cell algae. I don't have a market for tilapia so I use live bearers or older koi and it seems to work OK.

For the three-way thing, if it will run stable for 3-4 weeks I'm pretty happy and that is usually enough to get the fry off to a good start. However, you always need a backup - another green water source somewhere and another pond/tank ready to bloom zooplankton. Eventually, something will crash. I tend to crash them both at once. If the zooplankton numbers start dropping, I crank up the flow to get more algae in there. This will often wash out the green water. Other times, the fry pond will turn green and may even become the best source of green water. Often there is a day or so with low zooplankton numbers as the species composition changes from rotifers or Moina to copepods. When desperate, I go prospecting in other ponds and ditches with a 50 micron net on a long handle.

I see eggs with fungus but don't worry about them and don't use any chemicals or salt. But then, the problem is usually having more than enough fry for the space. Perhaps if you do some counts of fertilized versus non-fertilized eggs under a scope about 12 hours after spawning, and again after 36 hours, you will figure out whether the problem is fungus or fertility. The hard part will be getting a random sample because things tend to come in clumps. With all the commotion and splashing around at spawning, you would think koi would have fewer fertility problems than they do. Most people say to use not more than 2 males to protect the female. If available, I throw in 3 to 5 males but find that only one or two will monopolize most of the action so it's not much different for the female. However, the male doing all the work is seldom the one I want it to be. Also, it's not uncommon to have more fungus problems in a clear-water filtered hatching system than in a pond - probably because the biodiversity in the pond helps keep the fungus in check. I move the spawning mat straight to the pond(s) as soon as the adults have finished doing their thing. Less opportunity for me to screw up.

The little carnivore/cannibal koi can obviously do quite well on a diet of whole fish and seem to have little interest in eating their vegetables. I still want there to be some string algae and phytoplankton flock around so the koi get their vitamin-C. When culling, I toss small tategoi into a pond full of live-bearers (guppy, molly, swordtails, etc.) to get maximum growth from the koi and help keep the live-bearer reproduction in check. Thanks to the koi, the number of live-bearer fry in a pond will stay fairly low until the koi reach about 20 cm. Then, there seems to be a change in nutrition. They stop eating as many live-bearer fry and there is a population explosion. About the same time, the koi will start taking some fresh seaweed when it is offered - just like the adults. Intuition tell me this change is probably very gradual, but it sure seems distinct sometimes.

-steve hopkins

[ranskye]

hi again steve.
where is it you are, forgive me for being naive but i do not know my geography. sounds like japan or NZ but i dont think nz can have tilapia either, we are not allowed tilapia here but i sure know what you mean.
i can do the thing with the live bearers here too, i could never sell a whole pond of guppies and swords and platties, the market isnt big enough. but yes food for the best koi! brilliant. bet the koi eat my red swords and leave the browns and greens!!!!
ive seen what you mean, birds would pick up our koi and drop them in the livebearer ponds and they grew like rockets. likewize goldfish would hit full size in six months, you could tell the fish that had been reared this way even when they were old due to the size they gained.. i wasnt sure at first if it was just because they had a whole pond to graze on or it was the live guppy, then after seeing these rocket koi in amongst our select 4-5cm koi with 4 cm koi in their mouths i know it was the small fish. soon after id call it the growth from the "babies blood" all those little goodies they get.
another thing i thought is that even a predator gets its greens from within the stomach of what it is eating. say something eats 5 fish a day and everytime the prey fish has some greens in its guts and off they go!

so now its looking like i can have 9 ponds of highly nutrient algae water up top of the hill, feeding six ponds of rotifer, copepods ect and then six ponds of koi down the bottom that i will begin on a nutrient bloom also but gravity feed to when they run out, im begining to think that its likely that under this regime i will most likely be draining copepods and stuff bigger than rotifers down to the koi and goldfish as they will probably survive and grow well for the first week or so on the rotifers in theyre own pond and then want something bigger. i feel lucky to have the space to create my own food.

hmmmm begining to wonder how i would go comparitively with just 15 ponds of koi and supplemental feeding.. though the thing here is i cant just net all the ponds from birds at once so ill give this method a good flogging first.
weve got these birds round here thatll take out a thousand a day!!
they come in in flocks of 80 and spew up on the bank and then head out for more.

im pretty keen to see how this 3 way method goes in producing a pond full of fish and then checking on numbers, growth and water quality.
also my brother is dying to get his hands on a source of live feeds for all his cichlids.
we have these freshwater shrimp also that im gonna try, macrobachrium.
plus a smaller one that i dont know what it is. theyd make great live feeds for aquarium fish, i think they dont transport so well though but i plan to work it out. killed a whole bunch accidentally when i stumbled across them by draining a pond midday..
dont know about you but we can sell all our cullers to aquarium shops for feeders.

you know i was thinking of having like a little pump pumping away at night time with a light above it, pushing copees and the like into a drum screen and then draining it but now that i think about it sometype of floating mesh that is pulled through the water and harvested sounds ok too.

you know you could go super hi tech with computer controlled valves and auto sechhi type measurements but theres nothing like a good walk around a pond sometimes is there.
when i was a young bloke i used to get in the pond and drag one along and inevitably id be putting all this muck into them and my then boss would say how all the bad bacteria goes in amongst em and then the fish get a serve.

thanks for the tip on the microscope.. one day ill get this one fixed, its no good, ive had to use my eyes and a torch for everything here so far.

now to find me a whole heap of breeders... thats the next problem, 3 years to breed hey....not like the goldies..

oh one last thing! that sick fish (koi) was my old mans favourate platinum bright orange and it got stuck in the egg net and all day its been shaking its head up on the top of the water, like its got a nervous twitch or somethings stuck in its throat. it spins and shakes and twists.. almost like ammonia poisoning..but heavy gagging or gulping..there were two fish that were doing it but one came good.gills are clean and red. no signs of disease. think its an environmental one.
im thinking maybe a lack of oxygen has given it brain damage and its doomed.
any ideas??? i moved it away to a different tank but it still went on for over two hours.. ill probably find him dead in the morning..the tell tale stale eye..pretty hard to give the old man back a stale eye koi, harder to try find one the same here in australia! yeh better go and look at him again.

no do meter, no microscope, no ammonia test kit..some day steve, some day..

[bekko]

I'm in Hawaii ranskye. Moved here five years ago after retiring from more serious aquaculture. Love this place. Our family has about one hectare but most of it is in flowers, not fish. Your 40 ha would be the largest fish farm in Hawaii if it were here.
-steve