I Accidently Got A Fish Farm, Now What Do I Do.

[nmw]

Well i have arrived in thailand with the wife, and started to build to a house, this meant we had to dig a big hole on the farm, to raise the level of the land for the house and so what do we do with that?

Make a fish farm the wife says.

Well anyhow now the hole is complete, lined, re-inforced, it will be there after my death, and full of water, with about 20,000 little fish it.

Its a big pool at 26m*22m*7m deep.

The wife is down there every morning and every night feeding the fish, i do have experience with koi ponds and so ask the question How mush food do you give them, no idea is the basic reply.

After a couple of weeks the water is green and certainly stinks.

We need to put air into the water the wife says, so we fit pumps and suck it from the bottom and spay it over the top in plastic pipes with holes in them, looks good but no idea if it is working?

She goes to the local small fish farm and asks them what to do, they say you need to put this "DM" stuff in, its some sort of microbiological mixture, they make for themselves, put in 1 litre a day and all will be ok.

How do we make this stuff?

Well, i think, we get a big container, approx 300 litres, fill it with rotten food and crass cutting, some sugar and wait six months?, then you get a living brown liquid that will work wonders for the water in the fish farm. MMmm i see, what do we do in the meant time?

Well in the mean time the family in thier wisdom have deceided more air is the answer, do we use paddles in the water or do we buy this special for job airiators from bangkok at 125,000 Baht.

Time for me to get some real information now, before theis goes wild?

My question, where do i get information on setting up, maintianing, growing and equiping fish farms over here in english?, on the web?

Anybody got any idea on how to make the brown living stuff from garden and kitchen waste, and how much to use?

I do have experience in Koi ponds upto large sizes and understand water quality, think i can find a PH tester out here, with difficulty (I am in Wattana Nakhon, near Sa Kaeo, if we build a pool, which i intend to do, it will be the first in this town!)

Luckily, only a couple of dead fish as yet, i suppose thats run of the mill, but i do not to wake up in the morning and find an ocean of floating bodies

Appreciate all reply's, i've joinded this site after doing re-search today in the above, and the reading the many facinating stories and warnings, here we go again i think!!

Nigel

[ozzydom]

First thing is, what type of fish did you put in?

The pump setup you have installed is next to useless as far as aerating the water is concerned, what sort of pump are you employing?

Two ways that you can use a water pump to aerate,one is to put your spray bars horizontally about mid water and somewhere between the pump and where the outlet pipe enters the water you put a 30-45 degree tee piece with the branch angle heading back toward the pump, on this you put about a 4 foot length of hose . This works as a venturii and the water passing the angle draws in air and mixes with the pumped water.

The other way is to make up a nozzle of expanding size , for instance if you have a 3 inch centrifigal pump ,you can use off the shelf PVC fittings.. you can use a 3" female thread to 3" pipe fitting _ 1 foot of 3" pvc pipe_then a 3" to 4" reducer and finally 2-3 feet of 4" PVC pipe..... drill holes through the 3' pipe to put a 3/8 inch bolt horizontally slightly lower than centre ,this bolt will help agitate the water and start it cavitating to mix air into the water.

With this setup, you just set you pump on the bank and shoot the water onto the surface of the pond.

The standard aerator used here is using a truck supercharger (blower) on a 2hp electric motor , one of our members can supply you one for about 12k, PM me for his contact address. Your pond is far to small for a paddle wheel setup.

I would guess that you have put in catfish and would hazard a guess that they are being overfed by the water conditions you describe.

If you have put in Pla Nin then your problem is overstocking, a small pond ( 1/4 rai ) will only handle 400-500 fish as they grow.

If you have got Pla Nin ,no big problems yet as you can sell the fingerlings for probably 100% markup .

[Gary A]

If you want to keep any fish, I'd advise you to hire a 24 hour a day guard.

[IraqRon]

As far as the green water goes, the farmers in my area who have ponds by the rice fields bundle up rice straw into small sheaths and throw them into the pond, the amount depends on pond size, and this keeps the water clear. I am told that the decomposition of these rice sheaths creates a bacteria that eats the green slime. Apparently this is done even in the UK, so must be ok. You should be able to get the rice straw free so very cheap to do and don't think it eats up the oxygen in the pond water either.

Edited August 30, 2008 by IraqRon

[jaideeguy]

"She goes to the local small fish farm and asks them what to do, they say you need to put this "DM" stuff in, its some sort of microbiological mixture, they make for themselves, put in 1 litre a day and all will be ok."................I think she is saying EM, which is an enzyme mix that helps digest waste and it can be accelerated by diluting with molasis and water.

[TexasRanger]

My mother in law has a pond with Pla Nin, she just feeds them and doesn't add anything special, she has been doing it for years no problem and no green water, maybe you have too many fish?

[Maizefarmer]

You are going to have to get on top of the problem asap nmw, else you are going to have a mess on your hands.

Give this one some thought (I know nothing about keeping fish commercialy but I know a bit about cleaning up water - and although I haven't done this myself on the scale I am going to describe to you, it works with my small koi pond in the garden, and I have seen the same operating very efficeintly at a fish farm not far from Nakorn Ratchasima - and what makes it so effective is the depth of the pond avalible to work with - something around the same as yours).

Take one end of the pond - say about 3m -4m from the end wall (across the pond width of course - not length), and build a wall to section it off from the rest of the pond. Turn this area into a huge bio-filter.

It will offer you approx 1:6 volume (filter:pond) ratio - which will be a great volume for a very efficient bio-filter.

Keep in mind from an energy usage point of view: most effective gas exchange takes place at the surface (introducing air at depth is a great way to move water, oxygen/CO2 exchange across the water/air bubble surface tension takes place far better at the surface).

er ....... you slanted the bottom of the pond?

[joeuk1]

You are going to have to get on top of the problem asap nmw, else you are going to have a mess on your hands.

Give this one some thought (I know nothing about keeping fish commercialy but I know a bit about cleaning up water - and although I haven't done this myself on the scale I am going to describe to you, it works with my small koi pond in the garden, and I have seen the same operating very efficeintly at a fish farm not far from Nakorn Ratchasima - and what makes it so effective is the depth of the pond avalible to work with - something around the same as yours).

Take one end of the pond - say about 3m -4m from the end wall (across the pond width of course - not length), and build a wall to section it off from the rest of the pond. Turn this area into a huge bio-filter.

It will offer you approx 1:6 volume (filter:pond) ratio - which will be a great volume for a very efficient bio-filter.

Keep in mind from an energy usage point of view: most effective gas exchange takes place at the surface (introducing air at depth is a great way to move water, oxygen/CO2 exchange across the water/air bubble surface tension takes place far better at the surface).

er ....... you slanted the bottom of the pond?

MF

A koi pond is something i realy want to build at some stage .

Have seen some beautiful Koi near JJ market in Bkk how big is your Koi pond -how deep ?

Any chance of seeing photo .

Thanx JB

Edited August 30, 2008 by joeuk1

[mellow1]

This should be a good and informative website for you.

http://www.koiphen.com/forums/forumdisplay.php?f=108

[nmw]

Well i have arrived in thailand with the wife, and started to build to a house, this meant we had to dig a big hole on the farm, to raise the level of the land for the house and so what do we do with that?

Make a fish farm the wife says.

Well anyhow now the hole is complete, lined, re-inforced, it will be there after my death, and full of water, with about 20,000 little fish it.

Its a big pool at 26m*22m*7m deep.

The wife is down there every morning and every night feeding the fish, i do have experience with koi ponds and so ask the question How mush food do you give them, no idea is the basic reply.

After a couple of weeks the water is green and certainly stinks.

We need to put air into the water the wife says, so we fit pumps and suck it from the bottom and spay it over the top in plastic pipes with holes in them, looks good but no idea if it is working?

She goes to the local small fish farm and asks them what to do, they say you need to put this "DM" stuff in, its some sort of microbiological mixture, they make for themselves, put in 1 litre a day and all will be ok.

How do we make this stuff?

Well, i think, we get a big container, approx 300 litres, fill it with rotten food and crass cutting, some sugar and wait six months?, then you get a living brown liquid that will work wonders for the water in the fish farm. MMmm i see, what do we do in the meant time?

Well in the mean time the family in thier wisdom have deceided more air is the answer, do we use paddles in the water or do we buy this special for job airiators from bangkok at 125,000 Baht.

Time for me to get some real information now, before theis goes wild?

My question, where do i get information on setting up, maintianing, growing and equiping fish farms over here in english?, on the web?

Anybody got any idea on how to make the brown living stuff from garden and kitchen waste, and how much to use?

I do have experience in Koi ponds upto large sizes and understand water quality, think i can find a PH tester out here, with difficulty (I am in Wattana Nakhon, near Sa Kaeo, if we build a pool, which i intend to do, it will be the first in this town!)

Luckily, only a couple of dead fish as yet, i suppose thats run of the mill, but i do not to wake up in the morning and find an ocean of floating bodies

Appreciate all reply's, i've joinded this site after doing re-search today in the above, and the reading the many facinating stories and warnings, here we go again i think!!

Nigel

Thanks for the info so far

The fish in the pond currently (me translating from the wife) are

Pla Nin 8000

Pla Yissok 8000

Pla Jin 8000

The pump we are currently using is 1kw, pumping 300litres/min

Surprised at your suggestion of fish stocking levels, everbody is telling me we can go up to 80 tonnes of fish (80,000 at 1kg) as we have 3.5 million litres of water, pond is 7m deep.

The water has improved over the last few days and we are losing maybe 1 to 2 fish per day.

Will try to create the venturi you are talking about, got the basic idea

Do you have any idea on quantity of feed per day?, what is the feed/weight ratio of these fish, i.e how much food to grow the fish to 1Kg.

thanks for the reply

[nmw]

First thing is, what type of fish did you put in?

The pump setup you have installed is next to useless as far as aerating the water is concerned, what sort of pump are you employing?

Two ways that you can use a water pump to aerate,one is to put your spray bars horizontally about mid water and somewhere between the pump and where the outlet pipe enters the water you put a 30-45 degree tee piece with the branch angle heading back toward the pump, on this you put about a 4 foot length of hose . This works as a venturii and the water passing the angle draws in air and mixes with the pumped water.

The other way is to make up a nozzle of expanding size , for instance if you have a 3 inch centrifigal pump ,you can use off the shelf PVC fittings.. you can use a 3" female thread to 3" pipe fitting _ 1 foot of 3" pvc pipe_then a 3" to 4" reducer and finally 2-3 feet of 4" PVC pipe..... drill holes through the 3' pipe to put a 3/8 inch bolt horizontally slightly lower than centre ,this bolt will help agitate the water and start it cavitating to mix air into the water.

With this setup, you just set you pump on the bank and shoot the water onto the surface of the pond.

The standard aerator used here is using a truck supercharger (blower) on a 2hp electric motor , one of our members can supply you one for about 12k, PM me for his contact address. Your pond is far to small for a paddle wheel setup.

I would guess that you have put in catfish and would hazard a guess that they are being overfed by the water conditions you describe.

If you have put in Pla Nin then your problem is overstocking, a small pond ( 1/4 rai ) will only handle 400-500 fish as they grow.

If you have got Pla Nin ,no big problems yet as you can sell the fingerlings for probably 100% markup .

Thanks for the info so far

The fish in the pond currently (me translating from the wife) are

Pla Nin 8000

Pla Yissok 8000

Pla Jin 8000

The pump we are currently using is 1kw, pumping 300litres/min

Surprised at your suggestion of fish stocking levels, everbody is telling me we can go up to 80 tonnes of fish (80,000 at 1kg) as we have 3.5 million litres of water, pond is 7m deep.

The water has improved over the last few days and we are losing maybe 1 to 2 fish per day.

Will try to create the venturi you are talking about, got the basic idea

Do you have any idea on quantity of feed per day?, what is the feed/weight ratio of these fish, i.e how much food to grow the fish to 1Kg.

Tell me more about the blower from a truck, i suppose a 2HP electric motor uses a lot of power?

Where do we put the air afterwards?

Do you run this 24 hours/day?

thanks for the reply

[nmw]

If you want to keep any fish, I'd advise you to hire a 24 hour a day guard.

With the main house only 30 m away and 4 dogs outside, there are welcome to try, i would not want to face the dogs on a dark night!!!!

[nmw]

You are going to have to get on top of the problem asap nmw, else you are going to have a mess on your hands.

Give this one some thought (I know nothing about keeping fish commercialy but I know a bit about cleaning up water - and although I haven't done this myself on the scale I am going to describe to you, it works with my small koi pond in the garden, and I have seen the same operating very efficeintly at a fish farm not far from Nakorn Ratchasima - and what makes it so effective is the depth of the pond avalible to work with - something around the same as yours).

Take one end of the pond - say about 3m -4m from the end wall (across the pond width of course - not length), and build a wall to section it off from the rest of the pond. Turn this area into a huge bio-filter.

It will offer you approx 1:6 volume (filter:pond) ratio - which will be a great volume for a very efficient bio-filter.

Keep in mind from an energy usage point of view: most effective gas exchange takes place at the surface (introducing air at depth is a great way to move water, oxygen/CO2 exchange across the water/air bubble surface tension takes place far better at the surface).

er ....... you slanted the bottom of the pond?

Yes sides are slanted, had too, too deep for straight walls

They put re-inforcing concrete beams every 7 or 8 m or so, and then lined with sand and paving bricks, plastic pipes every 1m in all directions allow seepage in from the ground water level.

Worked well when the rains came, pool filles in 5 days

Tell me more about this bio filter, do i need pumps etc or what?

[nmw]

"She goes to the local small fish farm and asks them what to do, they say you need to put this "DM" stuff in, its some sort of microbiological mixture, they make for themselves, put in 1 litre a day and all will be ok."................I think she is saying EM, which is an enzyme mix that helps digest waste and it can be accelerated by diluting with molasis and water.

Yup

Still trying to get to use to the accent, the wife speaks good english, we get by well, but sometimes, a few letters get confused.

Any idea the best way to make the stuff

So far we have a 28gallon dustbin full of morning glory and food waste from the house, started it off with a litre of the stuff "em" we got from the farm, and putting everying in there that biological.

How long should it take

My thoughts are we need to liquidize the lot?

[nmw]

"She goes to the local small fish farm and asks them what to do, they say you need to put this "DM" stuff in, its some sort of microbiological mixture, they make for themselves, put in 1 litre a day and all will be ok."................I think she is saying EM, which is an enzyme mix that helps digest waste and it can be accelerated by diluting with molasis and water.

Yup

Still trying to get to use to the accent, the wife speaks good english, we get by well, but sometimes, a few letters get confused.

Any idea the best way to make the stuff

So far we have a 28gallon dustbin full of morning glory and food waste from the house, started it off with a litre of the stuff "em" we got from the farm, and putting everying in there that biological.

How long should it take

My thoughts are we need to liquidize the lot?

[Crushdepth]

I recommend you contact the nearest Department of Fisheries station if there's one in your area. They should be able to give you free technical advice about basic fish cultivation techniques suitable for your area. But you might want to have a good look about whether this really is economically viable as a business idea, or whether it might just be a good way to produce your own fish to eat!

Some publications may be of interest (all are free downloads from www.enaca.org, English-language aquaculture site):

Tilapia farming support tool (software)

Feeds and Feeding for Inland Aquaculture in Mekong Region Countries

Aquaculture Asia Magazine (latest issue, but have a look through back issues for useful articles).

Aquaculture fundamentals: Getting the most out of your feed.

Aquaculture fundamentals: Getting the most out of your feed Part II: The role of macronutrients

Aquaculture Fundamentals: A general approach to disease treatment & control.

Aquaculture Fundamentals: The use of lime, gypsum, alum and potassium permanganate in water quality management.

Economics of aquaculture feeding practices in selected Asian countries

Its a big pool at 26m*22m*7m deep.

Very deep! Most fish ponds usually no more than 1.5-2 meters deep. When you have a very deep pond like this you often get stratification of the water column and the bottom levels of the water may have little or no oxygen. You could consider lowering the water level or using paddlewheels to improve circulation and mixing, but they use a lot of energy and probably are not economic for what you want to do. Alternatively, you could stock fish that are capable of breathing air (eg. many kinds of catfish which will happily sit on the bottom and occasionally surface for a breath).

The wife is down there every morning and every night feeding the fish, i do have experience with koi ponds and so ask the question How mush food do you give them, no idea is the basic reply. After a couple of weeks the water is green and certainly stinks.

Ideally, you should aim to feed fish at a certain percentage of their body weight per day (varies according to species). Need to estimate the fish biomass in the pond to do that. What are you feeding them with? If you put too much nutrients in the water (food or fertliser) you can get excessive algal blooms. This is bad because the algae can i) deplete oxygen levels in the water during the night and ii) may suddenly die off and decompose, resulting in bacterial bloom and oxygen depletion. If you just want to produce a few fish for your own consumption (low stocking density) you may be able to get away with just lightly fertilising the water and relying on natural pond productivity to supply food for the fish.

We need to put air into the water the wife says, so we fit pumps and suck it from the bottom and spay it over the top in plastic pipes with holes in them, looks good but no idea if it is working?

This won't solve the water stratification problem. On a deep pond, one approach I've seen that works (and I'm not saying it is necessarily economic if you are trying to do this as a business) is to run perforated PVC pipes across the pond bottom, feeding air from a blower. This will supply oxygen, mix the water column and also help to break down the fish wastes that accumulate on the bottom of the pond.

Edited September 3, 2008 by Crushdepth

[Gary A]

If you want to keep any fish, I'd advise you to hire a 24 hour a day guard.

With the main house only 30 m away and 4 dogs outside, there are welcome to try, i would not want to face the dogs on a dark night!!!!

Good for you. Both ponds on two different farms have been poached and how they managed to get every single fish out of one pond is beyond me. My wife had nets ready when we were flooding rice paddies and she was VERY disappointed that there were absolutely no fish in the pond. That pond was pumped totally dry and there were NO fish in it. Thieving bastards.

[Crushdepth]

If they are using cast nets to steal your fish a coil of weighted barbed wire in the pond will discourage them.

[ozzydom]

nmw , you have not stated which area you reside ,(sorry, you did )

but as Crushdepth suggested , your first job is to contact the Fisheries Dept. in your area for advise as you have been given some absolutely bad advise to start with.

There is no way known that you are going to grow 1 kg fish with the stocking density you have. Fish ponds rely on surface area with regard stocking rates and not depth.

The normal stocking rate on a commercial basis using Pla Nin is 1000 fish per rai.

Whether you use intensive feeding or "green water " and supplamentory feeding, you can achieve fish 600 gram in about 8 months at that stocking density.

Water depths over 2 metres is useless as light does not penetrate anywhere near that depth so micro-organisms and phytoplanktons which need light to survive are going to be absent ,and these are some of the critters that assist in the breaking down of waste.

Result will be an ammonium soup ,toxic to just about anything

The microbiological brew that you are making is aerobic bacteria which in itself uses lots of oxygen to multiply and work at breaking down waste and just like in a sewage treatment plant where it is also used, it needs constant aeration to work.

Rule of thumb feeding is to slowly provide as much food as the fish can consume in 10-15 minutes /twice a day.

Unless you are using fertilized "green water" and only feeding supplementory pellets anything under 20% protein is fairly useless and with 30% protein pellets at between 450-500 baht per 20 kg margins are tight so your FCR is very important.

As water quality problems arise ,the ability to do water exchange is most important , which is to pump suspect water out and replenish from a clean supply such as a Klong.

I dont want to be a "wet blanket" but as a commercial fish farmer I would have to say that the advise you have been given from day one,is a recipe for disaster and that you should go back to the drawing board and start afresh with sound advise from the relevant people and departments.

[ozzydom]

If you want to keep any fish, I'd advise you to hire a 24 hour a day guard.

With the main house only 30 m away and 4 dogs outside, there are welcome to try, i would not want to face the dogs on a dark night!!!!

Good for you. Both ponds on two different farms have been poached and how they managed to get every single fish out of one pond is beyond me. My wife had nets ready when we were flooding rice paddies and she was VERY disappointed that there were absolutely no fish in the pond. That pond was pumped totally dry and there were NO fish in it. Thieving bastards.

Gary, it would be unusual to be able to net every fish out of a pond, there is a tree bark that thais use to deplete the oxygen in ponds and make the fish come to the surface where they can be scooped up , sounds like it was a concerted effort to me , as if they were netting over a period the fish would become so scarce as to make the effort to hard but some would remain.

[sunsamourai]

i Have no direct experience on fish, but I've been studying shrimp farming fro some time.

I found lots of professional info (in english) from Kasetsart university (department of fisheries), and the library from AIT - Rangsit.

Many kings projects on that field too.

Good luck for your research.

[JUICEBOX]

nmw , you have not stated which area you reside ,(sorry, you did )

but as Crushdepth suggested , your first job is to contact the Fisheries Dept. in your area for advise as you have been given some absolutely bad advise to start with.

There is no way known that you are going to grow 1 kg fish with the stocking density you have. Fish ponds rely on surface area with regard stocking rates and not depth.

The normal stocking rate on a commercial basis using Pla Nin is 1000 fish per rai.

Whether you use intensive feeding or "green water " and supplamentory feeding, you can achieve fish 600 gram in about 8 months at that stocking density.

Water depths over 2 metres is useless as light does not penetrate anywhere near that depth so micro-organisms and phytoplanktons which need light to survive are going to be absent ,and these are some of the critters that assist in the breaking down of waste.

Result will be an ammonium soup ,toxic to just about anything

The microbiological brew that you are making is aerobic bacteria which in itself uses lots of oxygen to multiply and work at breaking down waste and just like in a sewage treatment plant where it is also used, it needs constant aeration to work.

Rule of thumb feeding is to slowly provide as much food as the fish can consume in 10-15 minutes /twice a day.

Unless you are using fertilized "green water" and only feeding supplementory pellets anything under 20% protein is fairly useless and with 30% protein pellets at between 450-500 baht per 20 kg margins are tight so your FCR is very important.

As water quality problems arise ,the ability to do water exchange is most important , which is to pump suspect water out and replenish from a clean supply such as a Klong.

I dont want to be a "wet blanket" but as a commercial fish farmer I would have to say that the advise you have been given from day one,is a recipe for disaster and that you should go back to the drawing board and start afresh with sound advise from the relevant people and departments.

Nigel,

An excellent guide is available at the follwoing website: http://www.tilapiathai.com/inform/about.htm

just click the link to "manual". Easy to follow and these guys are very good in Tilapia farming, they can also provide you with equipment etc.

Good luck.

Justin