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Posted

I understand stratification and I agree with you that that this is a big binfet to balancing the temperature in the water along with aeration. Therefore I may try both with the water pump and venturi this may save me a lot of time in replacing the water. As most of you, my big concern is March, April and May when my water level is low and it is hot.

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Posted (edited)

Planning, not going to get a back hoe in there, to many structures around it now. 4 meters to the rock. we hit that on the big pond. wai2.gif

Edited by ray23
Posted

I have reviewed the venturi approach to aeration. I have several 3 horse motors available and to put the venturi tube in line is no problem. However, I believe that the Yuting Whirl air pump is a better approach. At 375 watts it is pulling about 1.56 amps. This has to be a lot more efficient than the 3 hp water pump-venturi combination.

Does anyone have an opinion on this issue of venturi water pump vs air pump and stone distribution.

Hi DB, In an overstocked 1200 sq met pond the choice is a no brainer imho.

There is no harm in fitting a venturii to your pump discharge line (have one I use most times when topping up or doing water exchange). But a venturii is to localised to aerate a pond 24/7, plus they tend to entice the fish to congregate at the outlet which has its own problems.

The HG 375 will run 40 stones at 70cm depth so giving coverage throughout the pond and is about 1/9th the running cost of a single 3hp motor (just remembered you have 3ph available).

every 2nd year we put the tractor in to clean up so my aeration pipework is joined with clear tube (11/2 ")and ss radiator clamps to enable easy disassembly and removal.

Posted

Well you have seen mine. most to the time the single outlet is more then enough, but my pond is 1/4th the size of yours. I think the only time frame I need more really is in April and May. I did put one in each floating net pond. Last try on that experience, simply not needed.

All the pumps in use 687 Baht month for electric ain't bad, which includes the satbadar household pump for watering mushrooms, Supplying it all with Solar would be about a 30K investment. But I;m on electrician so I'm gun shy of that one.

Posted

I have used these 3 hp pumps in the past to change water and they are expensive to operate. It takes about 18 hours for me to move 6 inches of water from the lower pond to the upper one.However, I think I will buy a gasoline pump with 4 inch intake and discharge. These are about 4500 Baht. The Chinese made pumps I have break down frequently.

Using the HG 375 air pump is my best bet. I just have to find a supplier in Chiang Rai who can order it for me.

Posted (edited)

I don't use those pumps to transfer water, I have six horse power Chinese pump for that. Other then oil changes and an occasional tunep in the three years no problems. But, maybe I got lucky. We have transfered water from 500 meters it handles it well.

Edited by ray23
Posted

I have used these 3 hp pumps in the past to change water and they are expensive to operate. It takes about 18 hours for me to move 6 inches of water from the lower pond to the upper one.However, I think I will buy a gasoline pump with 4 inch intake and discharge. These are about 4500 Baht. The Chinese made pumps I have break down frequently.

Using the HG 375 air pump is my best bet. I just have to find a supplier in Chiang Rai who can order it for me.

That is cheap for a 4 inch gasoline pump Donald, I use 3 inch Honda and Kubota centrifigals and they are 9k and 11k respectively,

I have "done in" 3 of the Honda i n the last 5 years, they have a habit of tossing in the crank seal and filling the sump with water,which leads to broken cranks, piston out the side of the block etc.Touch wood ,the Kubota is performing well.

Posted

OD: The gas pump that I am looking at is Chinese made. It is in a store almost next to makro in Chiang Rai. I appreciate your experience with the Honda pump. I can buy 2 Chinese pumps for the price of one Kubota but they always fail when you are needing them the most. Sure the Chinese pumps are less reliable than the Honda or Kubota. If you have had 3 Hondas to fail in 5 years for sure I don't want one of those.

I will have to have the air pump as well as the gasoline pump this next year. I don't like to have the outside Thais do the pumping and catching of the fish as they leave too many tilapia in the pond and this a big problem for me now. Have to set up some kind of net to try to get the tilapia out as they are very expensive to feed and of little value. Would be better to cook and dry them for fertilizer or fish food. I understand that when cooking to make fertilizer or fish food the stench is extremely bad and it takes several days to do the job. Maybe better to bury them and dig them up later for garden fertilizer.

Posted

OD: The gas pump that I am looking at is Chinese made. It is in a store almost next to makro in Chiang Rai. I appreciate your experience with the Honda pump. I can buy 2 Chinese pumps for the price of one Kubota but they always fail when you are needing them the most. Sure the Chinese pumps are less reliable than the Honda or Kubota. If you have had 3 Hondas to fail in 5 years for sure I don't want one of those.

I will have to have the air pump as well as the gasoline pump this next year. I don't like to have the outside Thais do the pumping and catching of the fish as they leave too many tilapia in the pond and this a big problem for me now. Have to set up some kind of net to try to get the tilapia out as they are very expensive to feed and of little value. Would be better to cook and dry them for fertilizer or fish food. I understand that when cooking to make fertilizer or fish food the stench is extremely bad and it takes several days to do the job. Maybe better to bury them and dig them up later for garden fertilizer.

I am a bit confused as to which Tilapia you are referring to Donald.

Posted (edited)

Me too. least expensive to feed that I have using the green method and sale for 70 baht kilo here, that's not that bad. What am I missing.

A lot of framers just use the green method.

Any chance you are over feeding?

Edited by ray23
Posted

The tilapia that I am trying to get rid of are the black pla nin that were not caught by the crew when the drained the pond and netted the fish. God only knows where so many of them came from that was. It appeared that they were getting most of them. I think I have more than 1000 that are there now and I need to get rid of them as I only want to feed the pa duk and the pla suwai.

Posted

The tilapia that I am trying to get rid of are the black pla nin that were not caught by the crew when the drained the pond and netted the fish. God only knows where so many of them came from that was. It appeared that they were getting most of them. I think I have more than 1000 that are there now and I need to get rid of them as I only want to feed the pa duk and the pla suwai.

Sounds like they are mixed sex and breeding,good luck, its almost an impossible task

.

The only way is to drain the pond completely, remove what you can and poison the water before restocking, but if the cats are already there its like sorting fly poo from pepper.

Mixed sex Tilapia start breeding at only about 250 grams.

Posted

I think my only hope of getting rid of the pla nin is with some kind of net and Thai fishermen. Hoping the that catfish will eat the eggs from next year hatch. This is really a big problem with no good solution other than draining the pond which I can't do. This pond is being set up for sport fishing. What a mess!

Posted

It is almost impossible to seine out all the tilapia in a pond. If you can't drain the pond, Rotenone is most likely your best solution. Catfish will not eat the tilapia eggs as they are in the mouths of the female tilapia, but the tilapia will eat the eggs of most predators that you stock to control them.

Posted

Thes black devil pla nin are the kiss of death. When they drained and netted my 1 Rai pond they took away 2 pick up truck load of these things. None were more than 10 inches long even though they had been in the pond for 10 years. They were fed by my staff every 3 days for 8 years and they never amounted to anything except trash. Now, I can't drain again as I have lots of baby catfish. There must be some kind of net or trap that can be put in to catch these devils. I looked on the internet and cant find fish traps.

Posted

I fully agree with Ozzydom's opinion. How big are the catfish? Do you only have one pond? How much do you have invested in the catfish?

Sometimes you have to bite the bullet and take the loss to start afresh (and do the job properly)

We have several times over the years bought mono-sex fry only to find months later that the testosterone treatment for whatever reason did not work and you end up with a pond of breeders.

All we could do was pump the pond ,dig a bloody big hole to bury them ,Rotenone and refill and hope the replacement fry are up to par.

Cutting losses is usually better financially than fore going 200k because the fish did not grow.

Posted (edited)

Talk about losses... How many of you fish farmers out there know about wholesalers' cheat and tricks.

In the catfish arena, there's a few tricks that wholesalers use to cheat pond owners. Just be vigorous, the cheats come in form of weighing scale modification to standard basket alteration. Light cheating range from 200gm-400gm and heavy cheating from 1kg - 3kg... per basket load. smile.png

I got rid of them all.

*Do the maths... If my yield forcast is 24 tonnes, per basket load is 50, losses is 2 kg per basket base on cheats.

I would have lose 960kg. That would be losses equal to more than ฿46'000.

Warning's served~

Happy Farming.

Edited by RedBullHorn
Posted

RBH I have also heard about the fish broker cheats. When I sell mine. I will use my scales and baskets supervised by my wife and myself. Every time you turn around they are trying to do it to you.

Has anyone tried using ground coconut meat as fish food. I am told that it is very cheap as the grade is not good enough for the open market.

Posted

I have 5,000 catfish fry and 2000 pla suwai in a one Rai pond. There must be at least 1,000 or more of the pla nin left over that the drainers did not get. The catfish seem to be developing reasonably well. They are 7 weeks old and look to be about 5 inches long. The fisheries guy said that the catfish should be one kg by the end of the 3rd month. I don't believe him.

With the pla nin swarming and eating a lot I am hoping my money will hold up to buy feed. This like is spring fed and long. While pumping the lake kept getting water back into it in april. It may not be able to get all the fish out so the poison after wards may be the only way to get the pla nin out. Is it practical to use nets to try to catch the pla nin while they are swarming.

Posted

I don't know about nets and this would be one heck of a job with the numbers you have. Pla Nin are easy to catch with hooks and worms or other bait. Cat fish once you catch one like that it becomes very hard to catch them again..

You don't need anything fancy a bamboo pole and a float we use chunks of styrofaom line and a hook. This is how we do it a we don't sale in bulk.

Wana be a hero invite people over for a free catch um. Or fish them and sale them locally.

If you happen to catch one you want to keep. toss it back in.

I haven't yet seen cat fish at a kilo in 90 days. But, I have not used RBH's method yet either. But, local Thai;s here at laest don' want themat a kilo and you can sale around that time frame.

My pound is about 1/4 a rai so I do things very differently then guys who have 1 rai ponds.

Dom and RBH know what they are doing, just trying to offer a different thought

Netting the swarm hey maybe, you can always seperate the ones you want to keep. But if they are breeding, I guess you have to ride it out or get rid of all the fish.

We are running into that now, so I will empty the pond in March. to make sure I have enough water I will pump into a neighbors pond and then refill my pond.

Dom how does that posion work. I assume a small amount of water at the bottom. do you have to pump it out again or do you wait and add water?

Donald anyway you do it ain't going to be fun.

Posted

I have 5,000 catfish fry and 2000 pla suwai in a one Rai pond. There must be at least 1,000 or more of the pla nin left over that the drainers did not get. The catfish seem to be developing reasonably well. They are 7 weeks old and look to be about 5 inches long. The fisheries guy said that the catfish should be one kg by the end of the 3rd month. I don't believe him.

With the pla nin swarming and eating a lot I am hoping my money will hold up to buy feed. This like is spring fed and long. While pumping the lake kept getting water back into it in april. It may not be able to get all the fish out so the poison after wards may be the only way to get the pla nin out. Is it practical to use nets to try to catch the pla nin while they are swarming.

It looks as if you may have to persevere with growing the cats until market size,then harvest everything.

You will probably need extra pumping capacity to keep the inflow at bay,a 6 inch long tail pump moves a lot of water, if you can arrange a bulk sale you should be able to harvest in a day discarding anything you cant sell and load the pond up with Rotenone, fish kill should be attained in 24 hrs after that just let the pond refill naturally.

Rotenone breaks down quickly and I have found no residual problems.

You could let the locals thin out the Pla Nin with fairly large mesh cast nets (freebies) as long as they under supervision ,and dont let them use fine mesh lift nets or your cats will be taken as well.

Posted

Fish farming for a former rocket scientist in a banana republic is a lot of fun but my wife keeps saying"show me the money". The frigging money is going into feed. However, I must say that the feeding that I am doing on the upper lake with pla tab tim and the lower lake with pla sawai and pla duk seems to being going ok in spite of the left over plan nin. However, as these fish get larger I have to increase the daily feed in order for them to mature and this is when it is going to get expensive. Maybe I have to stick up a liquor store or stop feeding my wife's family to get the money.

There is an old saying that says "if we could live long enough we could really be smart".

Posted

RBH I have also heard about the fish broker cheats. When I sell mine. I will use my scales and baskets supervised by my wife and myself. Every time you turn around they are trying to do it to you.

Has anyone tried using ground coconut meat as fish food. I am told that it is very cheap as the grade is not good enough for the open market.

Donald,

how cheap is it? can you put a solid number on it, or it is just a "i heard, or i was told...myth"

do you in fact know a supplier? or that also myth.

i am sure catfish likes coconut, as much as other things, for the right price it could be part of the diet, but i dont think it would be the top pick if you rear the fish fully commercial way. RBH pointed out a few times before, that rearing time is key, shortens the recovering of cash, lessens the chance of a disease, and most importantly maximises the profit potential from the given pond.

Posted (edited)

Not sure about the price of the grated coconut meat but will explore on my next trip to town which is not too often.

from google===

Fish

Copra meal is a possible feed ingredient for fish though not a very good one. As a protein source, it contains much less protein than fish meal or soybean meal, and it is deficient in lysine and sulphur amino acids. While it is a good source of arginine, there is an antagonistic effect of excess dietary arginine on lysine metabolism and animals fed high dietary levels of copra meal may suffer from lysine deficiency (Tacon et al., 2009). Supplementary lysine and methionine should be provided to fish fed copra meal (Hertrampf et al., 2000). Copra meal may also contain anti-nutritional factors, including phytic acid, tannins, and non-starch polysaccharides (Tacon et al., 2009). The high crude fibre content of copra meal is disadvantageous for aquatic feeds (Hertrampf et al., 2000).

Copra meal is more valuable to herbivorous and omnivorous fishes (at 5-15 % inclusion rates) rather than to carnivorous fishes (at 5-10 % inclusion) (Hertrampf et al., 2000).

Edited by ozzydom
Posted

In regards to 1kg Pla Duk in 90 days...

Pla Duk Lart Sia 1kg+ in 90 days, fingelings size 3''-4''. (big percentage in a single pond feeding to satiation)

Pla Duk Big Oui 600gm +- in 90 days, fingerlings size 3''-4''.(slight percentage in a single pond feeding to satiation)

Posted

One for the Pla nin (and potential Pla Nin Farmers) ... does anyone consider raising Prawns/Shrimp as the same time as growing the fish out?

Posted

One for the Pla nin (and potential Pla Nin Farmers) ... does anyone consider raising Prawns/Shrimp as the same time as growing the fish out?

Into 2nd year of trials now,nothing to report as yet, will report when we start harvesting Pla Nin (and hopefully a few koong).

These are giant freshies (not white shrimp as outlaws do biggrin.png )

Placed 10,000 post larvael in each of two ponds.

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