Fish Farming ... When It Goes Belly Up

[ozzydom]

This week I met with Fisheries Department in Wian Chai. I counted the number of people they have working there and the total is 40. They were very kind and helpful. I was given a complete set of booklets on fish farming all in Thai.

Regarding a feeding regime for Pla Tab Tem and Pla Suwai they recommend daily feeding amounting to 3% of the fish body weight. For example if you had 1000 fish that average 150 grams then you would be feeding 4.5 kg of 25% percent protein. Naturally this is an estimate and a rule of thumb. It does apply to my application.

After 4 months, I am not able to experience growth of 100 Grams per month like some of you have. They did mention that you should increase the feeding monthly as the weight increases accordingly. Also mentioned that when you are approaching satiation you should reduce the feeding as there is demishing returns. If I can harvest both ponds after 9 months of feeding I will feel lucky.

, Feeding to satiation is very hard to monitor with Pla Nin and Pla Tab Tim as these fish have a two stomach anatomy,when the primary stomach is full any excess food passes to a secondary stomach and exits without being digested and so is of no benefit to the fish.

I have read of fantastic results from American studies Where they feed smaller amounts up to 10 feeds per day.

These fish have marked growth cycles,which are governed by genetics,water temperature, season etc, from my experience they get to about 400 gram pretty quickly then rate of growth slows markedly,they seem to take forever to get through the 500-550 gram stage then they start to put the weight on again.

Good oxygen levels and water quality are paramount to your fish eating well and utilising that food.

There is no formula you can apply to weight gain as when they are fry or fingerlings they may double in weight each month which is 100% gain per month but when they get to say 300 gram if they put on 20% the increase is 60 gram,at 500gram a 20% increase is 100 gram per month and so on. The bigger the fish the more food it can take up and the more weight will be gained.

The cage net growers in the Mekong claim to get their fingerlings to 1kg in 5 months but they have the advantage of constant flow of oxygen rich water through the net(usually but not always) and multiple feedings of high protein food each day.

I was concerned about our fishes weight gain a month or two ago so changed feed to CP 16.5 and am now seeing good results. Just like there are apples and apples, there are also feeds and feeds.

[ozzydom]

This week I met with Fisheries Department in Wian Chai. I counted the number of people they have working there and the total is 40. They were very kind and helpful. I was given a complete set of booklets on fish farming all in Thai.

Regarding a feeding regime for Pla Tab Tem and Pla Suwai they recommend daily feeding amounting to 3% of the fish body weight. For example if you had 1000 fish that average 150 grams then you would be feeding 4.5 kg of 25% percent protein. Naturally this is an estimate and a rule of thumb. It does apply to my application.

After 4 months, I am not able to experience growth of 100 Grams per month like some of you have. They did mention that you should increase the feeding monthly as the weight increases accordingly. Also mentioned that when you are approaching satiation you should reduce the feeding as there is demishing returns. If I can harvest both ponds after 9 months of feeding I will feel lucky.

Donald, the 3% of bio-mass feed ratio they recommend is the reason I use the green water method of growing.

Three of our ponds now have a bio-mass of between 1500 and 1800 kgs each,but we only feed 4.5 kg of pellets per day to each pond instead of the 45-54 kg we would using the 3% ratio giving me a feed saving of about 800 baht per day per pond.

[DonaldBattles]

OD: If I can get through this growing season and decide to grow Pla Tab Tem again I will surely start with the green algae approach as the food cost is dramatically reduced. I will get the green algae up good before putting the fish in.

Today while feeding in the morning I saw several cat fish mixed with the pla suwai and tab tem. This tells me that all 5,000 cat fish did not disappear. Further, I don't see how they could how swam 200 years and escaped through a 10 inch pipe which was not flowing strongly in 1 day until I got the screen on the discharge. Strange where these fish went to. There may be many of them left but just not showing at feeding time. I notice that the pla suwai follow me as I am walking the banks and feeding them. This leaves me with the wrong impression of how many are there. Tomorrow I will try to net a few and way them. They seem to be growing OK but it is difficult to measure.

[DonaldBattles]

Should have been 200 meters rather than 200 years. Excuse the error.

[RedBullHorn]

This week I met with Fisheries Department in Wian Chai. I counted the number of people they have working there and the total is 40. They were very kind and helpful. I was given a complete set of booklets on fish farming all in Thai.

Regarding a feeding regime for Pla Tab Tem and Pla Suwai they recommend daily feeding amounting to 3% of the fish body weight. For example if you had 1000 fish that average 150 grams then you would be feeding 4.5 kg of 25% percent protein. Naturally this is an estimate and a rule of thumb. It does apply to my application.

After 4 months, I am not able to experience growth of 100 Grams per month like some of you have. They did mention that you should increase the feeding monthly as the weight increases accordingly. Also mentioned that when you are approaching satiation you should reduce the feeding as there is demishing returns. If I can harvest both ponds after 9 months of feeding I will feel lucky.

Both points were mentioned in past post... #323

......As Ozzydom said, it is correct that food intake is base on bio-mass (body weight), ranging from 9% for fries, 5% for fingerlings to 3% adult catfish. (catfish display greedier trait when rear semi-intensive/intensive compare to living indiviually in stream where it will need only 1.5%)......

　

......Feed are increase according to the ability of fishes daily consumption.

At the end of 7th day, they will be eating 6/10 per day out of......

Donald, my concern is this...

You didn't have catfish even though they said they did sold you. I seriously doubt that you have the correct numbers of Tilapia you bought from the fingerlings shop......from what i saw and analyzes at your place.

I did farm Tilapia in the past before switching to Clarias, i know what a pond full of Tilapia looks like.

Here's a short clip of Tilapia being harvest i shot in the past...

[DonaldBattles]

God only knows if I got cheated when I about the fry. When I make a visual count of the pla tab tem I can't come up with any where near 2000. With regard to the catfish there a truck load of plastic bags with 500 per bag. Don't know if I was cheated or not.

As a beginner in this game I still have a lot to learn. When OD posted the biomass to feed information I did not understand but now I do. Bare with me until I can get through this season.

Today the temperature dropped and so did the barometric pressure. The pla tab tem were not interested in eating and were not active. The pla suwai showed a big drop in the willingness to eat. Has anyone else experienced this phenomenon?

[ozzydom]

God only knows if I got cheated when I about the fry. When I make a visual count of the pla tab tem I can't come up with any where near 2000. With regard to the catfish there a truck load of plastic bags with 500 per bag. Don't know if I was cheated or not.

As a beginner in this game I still have a lot to learn. When OD posted the biomass to feed information I did not understand but now I do. Bare with me until I can get through this season.

Today the temperature dropped and so did the barometric pressure. The pla tab tem were not interested in eating and were not active. The pla suwai showed a big drop in the willingness to eat. Has anyone else experienced this phenomenon

Donald,I spent 35 years at sea as a commercial fisherman, I faithfully documented every day of those more than 10,000 days,things like weather,tide,barometric pressure, water temperature ,phase of the moon etc.

I can honestly say that I was still no wiser as to why on certain days the fish bit like there was no tomorrow or the lobsters crawled into my pots like lobster Ramadam had just finished and on similar days nothing,nix, nada.

Maybe that was the attraction the industry holds for me.

[DonaldBattles]

OD: My god what a wonderful experience you must have had as a commercial fisherman for 35 years. I have always found fish to be fascinating. At one time I had a bass fishing show on TV in he USA. Just watching fish from my main sala that sits between the 2 lakes is really interesting. I look forward to feeding the fish 2 times per day. As an old retired rocket engineer I find fish farming very enjoyable. I love communicating with you guys on the forum. I also really appreciated RBH coming to visit me. He is a great guy who knows what he is doing.

[RedBullHorn]

I appreciate your hositality too Donald and thank you for your good words.

Donald, a word of advise which I'm sure of that Ozzy would agree.

Do Not Feed Your Tilapia (Nile or Red) when ever that's an overcast day. Period ! Even if it's 3 days in a row.

Never mind if they are hungry (let them feed on water will do ) Watch your area/region climate

and know your weather forcast from internet or TV news in advance. It's critical to be well prepare in advance.

The moment you wake up and exit that door after sunrise, look at the sky, smell the air...your senses will kick in if you sense that's a change in atmospheric different. (I do that every morning without fail all this years, it becomes a second nature, a habit. You were a Nasa engineer...you know what i mean.)

You do not want to wake up to a pond full of floating whites.

A sudden heavy shower or low pressure will deplete the pond's DO. Aeration in any form or method is a "must-have" equipment. The easiest and low cost method is a high HP pump to suck up the pond's water and deliver back into the pond, make sure the outlet part are position high to create splashes upon hitting the water surface.

As for my Clarias farm, overcast days is of no concern but temperature do matter (affect all type of fishes not only catfish). Fishes of all type are affected by temperature, when the weather get cooler, it lower the fishes' metabolic rates, they sense it's colder so the effect of hibernation, digestion slow down.

Every drop of 2°C in temperature will incur in a loss of appetite of about 13-15%. As for the voracious Clarias, they simply stop feeding at temperature 15°C during the morning cool but start to eat heartily in the afternoon at 2pm (marked) when temperature at 30+°C .

Good luck.

[DonaldBattles]

RBH: Many thanks for the atmospheric effects on fish farming. I shall pay close attention to the overcast days. I have barometer on my wireless station. I can also feel to drop in pressure. Yesterday the red tilapia simply would not eat. However, the splashed the water most of the night. The pla suwai were real slow about eating.

[canuckamuck]

Good post RBH about feeding and weather conditions. I know that my Tab Tim are very responsive to temperature and sunny skies. If the water temp is below 22, the amount they eat is reduced considerably. When the sun is out they eat more, and when I get the DO up they eat more as well. If I have all three conditions to the good, they can eat every 20 minutes it seems.

BTW, do any of you guys know where to get a DO test kit. I tried to find one while I was in Canada, but had no luck.

Because I am running tanks, it is very useful to measure DO gains when tweaking the system.

[RedBullHorn]

I know Namsai farm sells them...Ozzydom would know of more places that carry them.

[ozzydom]

RBH: Many thanks for the atmospheric effects on fish farming. I shall pay close attention to the overcast days. I have barometer on my wireless station. I can also feel to drop in pressure. Yesterday the red tilapia simply would not eat. However, the splashed the water most of the night. The pla suwai were real slow about eating.

Yep, great post from RBH (as usual)

Here is a link to a paper on Oxygen depletion which is very easy to comprehend.

warnell.forestry.uga.edu/warnell/service/library/index.php3?docID=183

[ray23]

Ok just a few thougths I noticed that on rainy days Pla Nin don't eat. That graduation from 1/2 kilo to one kilo is a long time. Catfish we have here can and do migrate. if the get into pla nin fry, that might be lunch. We messed up and didn't put netting around the cat fish pond. 50% were gone by the time we pumped the pond.

So you may not have been cheated.

Just a thought

If yuo enjoy it you will stick it out and you will learn. But, something to keep you busy has a value

[canuckamuck]

Thanks for the info

[DonaldBattles]

RBH what do you mean when you say that you lost 50% of the catfish util you put the nets up. What kind of nets? Were these to keep the catfish from jumping out?

Today all of my orange tilapia are suspended on top of the water without movement. I did not try to feed them because they won't move. Pla Suwai ate OK.

[ozzydom]

RBH what do you mean when you say that you lost 50% of the catfish util you put the nets up. What kind of nets? Were these to keep the catfish from jumping out?

Today all of my orange tilapia are suspended on top of the water without movement. I did not try to feed them because they won't move. Pla Suwai ate OK.

If they were just laying at the surface sucking air, it is an indication of oxygen depletion,the

next stage is ,off they go to fishy heaven.

I would strongly recommend you to get your aeration set up poste haste.

[ozzydom]

Good post RBH about feeding and weather conditions. I know that my Tab Tim are very responsive to temperature and sunny skies. If the water temp is below 22, the amount they eat is reduced considerably. When the sun is out they eat more, and when I get the DO up they eat more as well. If I have all three conditions to the good, they can eat every 20 minutes it seems.

BTW, do any of you guys know where to get a DO test kit. I tried to find one while I was in Canada, but had no luck.

Because I am running tanks, it is very useful to measure DO gains when tweaking the system.

Farmaqua have all testing kits,I think the DO kit is about 17usd.

Give Angus a ring on 0818052962 ,they will post or EMS

[RedBullHorn]

RBH what do you mean when you say that you lost 50% of the catfish util you put the nets up. What kind of nets? Were these to keep the catfish from jumping out?

Today all of my orange tilapia are suspended on top of the water without movement. I did not try to feed them because they won't move. Pla Suwai ate OK.

ray23 said that...not me.

[RedBullHorn]

The reason not to feed Tilapia when there's overcast days is because digestion uses energy and require more oxygen to do so. No sunlight means no photosynthesis at work, algae start to do the reverser of abstracting DO and produce CO_2....and graduate to DO depletion in a matter of time.

The next thing is the missus comes running, shouting "Pla knock ! Pla knock !" (knock out)

[RedBullHorn]

Ok just a few thougths I noticed that on rainy days Pla Nin don't eat. That graduation from 1/2 kilo to one kilo is a long time. Catfish we have here can and do migrate. if the get into pla nin fry, that might be lunch. We messed up and didn't put netting around the cat fish pond. 50% were gone by the time we pumped the pond.

So you may not have been cheated.

Just a thought

If yuo enjoy it you will stick it out and you will learn. But, something to keep you busy has a value

A well constructed pond layout with good dykes design are good enough to prevent any losses. My fish count and yield are on target everytime, sometime over the targeted harvest yield.

[ozzydom]

The reason not to feed Tilapia when there's overcast days is because digestion uses energy and require more oxygen to do so. No sunlight means no photosynthesis at work, algae start to do the reverser of abstracting DO and produce CO_{2 .}

_{The next thing will be the missus comes shouting... "Pla knock ! Pla knock !"}

Good comment RBH, I learnt the hard way when we started out a few years ago,its no fun burying a couple of tonne of Pla Nin.It was a lesson I have tried hard not to repeat.

One of the reasons why I so strongly advocate having ponds set up properly prior to introducing the fish.

[ozzydom]

Ok just a few thougths I noticed that on rainy days Pla Nin don't eat. That graduation from 1/2 kilo to one kilo is a long time. Catfish we have here can and do migrate. if the get into pla nin fry, that might be lunch. We messed up and didn't put netting around the cat fish pond. 50% were gone by the time we pumped the pond.

So you may not have been cheated.

Just a thought

If yuo enjoy it you will stick it out and you will learn. But, something to keep you busy has a value

I doubt that your cats wandered off Ray, your banks are to steep and they would have trouble scaling your concrete block perimeter fence.

Poachers would be my guess.

[RedBullHorn]

Considering your concrete perimeter fence from photos of your past posts, i second Ozzy comment.

Poachers.

[DonaldBattles]

This crappy weather is supposed to clear by tomorrow.I see a little movement of the pla tab tem and nin but not much. Most are on top breathing. The rain here has been very light and very much of it.

[ozzydom]

This crappy weather is supposed to clear by tomorrow.I see a little movement of the pla tab tem and nin but not much. Most are on top breathing. The rain here has been very light and very much of it.

If they are still distressed at this time of day,I would have a pump of some description in there trying to get a bit of circulation and aeration going,midnight till sunup is the critical time when DO is at its lowest.

If they are still in distress by late afternoon you could lose the lot.

[DonaldBattles]

I have a lot of pla nin left over in the lower lake which is a lot larger. I do not see any of them on the surface like in the upper lake. This probably means that the lower lake which is spring fed has more oxygen in it. The pla suwai there are eager to eat under the rainy conditions.

[David48]

This crappy weather is supposed to clear by tomorrow.I see a little movement of the pla tab tem and nin but not much. Most are on top breathing. The rain here has been very light and very much of it.

If they are still distressed at this time of day,I would have a pump of some description in there trying to get a bit of circulation and aeration going,midnight till sunup is the critical time when DO is at its lowest.

If they are still in distress by late afternoon you could lose the lot.

Donald, what ozzydom writes above shouldn't be undervalued.

I started this thread when the pond has an issue.

If you never had to clear a pond of dead fish ... then this might be a guide ...

Do start that aeration NOW and remember the low point is not long before Dawn.

If the fish are showing signs of stress now, you might awake to a pond of floaters.

.

[DonaldBattles]

My maintenance people can not be here before Monday. I will start working on the aeration system then. In the meantime all I can do is pray. So far no deaths.

[RedBullHorn]

The day you have floaters, you will learn...