Tilapia Saturation

[nellyp]

I have done a search on Tilapia but could not find this info....so.

On our farming adventure we have decided to farm some fish . I thought this was going to be catfish but apparently it will be Tilapia . 1000 fish in a net that appears to be 15 metres X 15 metres and is definately 1.2 metres deep. This seems unbelievable to me . Would this be possible? I was thinking about digging a pond of 1 rai so how many Tilapia could I get in that??? As a real point of concern, in a static pond what do you do about the waste from the fish? and could I have different fish in the pond co-existing and having some kind of symbiotic relationship.....eating each others shit would be some kind of dream I suppose . Also do Tilapia eat the same food as catfish?

Any help would stop at least part of my chagrin :jap:

Cheers

Neil

[Sinblesser]

Hey Nelly,

In my most honest opinion to the best of my knowledge,

Your fishes are gonna eat sleep and sh1t in that net. It'll choke at some point of time (i presume you're using the standard blue nets widely available). Then regardless if you place the net in a static pond or the Mekong River itself, you'll still be facing water conditions and waste build up in that 15 X 15 X 1.2 square.

Will you be aerating the water? Any filtration system to combat nitrate, nitrite and ammonia levels?

For species co-existing together, Pla Nin (Tilapia) and Pla Duk (Walking Catfish) are generally peaceful. But make sure you don't mix juvie Pla Nin with market sized Pla Duk or the other way round. Both species are omnivorous.

Expect casualties, those that are stunted will not survive amidst the competition for food and will fare much worse with bad water parameters. Counter this by paying more attention to water conditions (test kit) and feeding small amounts but regularly. DO NOT compensate for this by buying more fish be it at start or as a "top up".

Hope this helps, please feel free to correct me.

Cheers,

Sinblesser

Edited October 25, 2010 by Sinblesser

[nellyp]

Hey Nelly,

In my most honest opinion to the best of my knowledge,

Your fishes are gonna eat sleep and sh1t in that net. It'll choke at some point of time (i presume you're using the standard blue nets widely available). Then regardless if you place the net in a static pond or the Mekong River itself, you'll still be facing water conditions and waste build up in that 15 X 15 X 1.2 square.

Will you be aerating the water? Any filtration system to combat nitrate, nitrite and ammonia levels?

For species co-existing together, Pla Nin (Tilapia) and Pla Duk (Walking Catfish) are generally peaceful. But make sure you don't mix juvie Pla Nin with market sized Pla Duk or the other way round. Both species are omnivorous.

Expect casualties, those that are stunted will not survive amidst the competition for food and will fare much worse with bad water parameters. Counter this by paying more attention to water conditions (test kit) and feeding small amounts but regularly. DO NOT compensate for this by buying more fish be it at start or as a "top up".

Hope this helps, please feel free to correct me.

Cheers,

Sinblesser

Believe me maye, I am not going to correct anybody. I too believe that there will be way too many fish but am bowing to the (apparently) greater knowledge of the step brother. I am also worried about waste products and their removal (how long can these fish survive before the water is un-livable). I am also concerned that I thought Tilapi lived in water deeper than 1 metre. I think the brother in law, who has a tiny pond 2metres x 1 metre with some catfish growing in it, has seen an opportunity to use his little knowledge of catfish, and applying that to something he feels is a more profitable. He has nothing to lose but will have a share of the profit if it works.

I have asked them about aeration but they feel the plants living on the pond will sort this out. I thought that may be true for catfish but am unsure about Tilapia. I am thinkng that a water test kit could be a good idea but have no idea of cost, or where to get one. The missus has just told me the department for fish is near where we live in Sisaket so i may take a trip with her to there. i think I might be able to get more understandable advise from here.

Thanks for the input

Neil

Edited October 25, 2010 by nellyp

[Sinblesser]

Believe me maye, I am not going to correct anybody. I too believe that there will be way too many fish but am bowing to the (apparently) greater knowledge of the step brother. I am also worried about waste products and their removal (how long can these fish survive before the water is un-livable). I am also concerned that I thought Tilapi lived in water deeper than 1 metre. I think the brother in law, who has a tiny pond 2metres x 1 metre with some catfish growing in it, has seen an opportunity to use his little knowledge of catfish, and applying that to something he feels is a more profitable. He has nothing to lose but will have a share of the profit if it works.

I have asked them about aeration but they feel the plants living on the pond will sort this out. I thought that may be true for catfish but am unsure about Tilapia. I am thinkng that a water test kit could be a good idea but have no idea of cost, or where to get one. The missus has just told me the department for fish is near where we live in Sisaket so i may take a trip with her to there. i think I might be able to get more understandable advise from here.

Thanks for the input

Neil

Water depth wise, i prefer deeper water simply because it prevents fluctuations of temperature. But you're keeping them in a pond, so this is redundant. If your pond is shaded it should be fine for a meter as depth or put some surface plants for them to shelter under.

If all else fails, get a net and do regular scooping of waste and dead fish(hopefully none).

I do quite disagree on the water plants providing adequate Oxygen(O2) part. You may have pearlings or saturating of O2 in the pond if your water plants are in good shape but without proper WATER CIRCULATION entering and exiting the net the O2 counts for nothing.

Catfish can survive in low levels of O2 which the Tilapia simply cannot match.

There are other things to consider, the murkiness of the water? Without sunlight how are the plants gonna photosynthesis? If it's algae causing the murk then you're quite certainly having an O2 problem as algae consumes oxygen. If they're present in such abundance to murk the water they're causing quite a fair bit of O2 starvation for your fish. Please see if your Tilapias shows signs of O2 starvation.

I'm using API Freshwater Master Test Kit. Not sure about forum rules on links, mods please remove if deem fit.

Sorry i cannot advise on price and place since i brought this over into Thailand from Singapore but i'll look into it and give you the heads up.

If you're in Sisaket and you're planning to head over to the department for fish... If it's the "Inland Fishery Museum" at N16,10.575, E103,16.46 I've been there. Didn't help too much but worth a try. Farms along the road leading to it offers cheap low grade tilapia and other fish that's great for experimenting.

Hope this helps,

Sinblesser

[RedBullHorn]

The spec for tilapia is 4'000 per rai so 1'000 would be 1/4 rai ( 3 fishes/m3 ) at water level depth of 1m, but no more than 1.5m is prefered.

RBH.

[RedBullHorn]

you may want to consider herbivorous feed for tilapia, they do eat catfishes feed but it much cheaper if you feed they specialise tilapia feed.

[ozzydom]

nellyp,the ordinary fine blue mesh hapa,s are not suitable for growing on Tilapia.

These are ok to rear to fingerling stage but then specially constructed (and expensive ) nets with at least a 1/2" mesh and preferably 1" with a band of fine mesh around the water line (to stop feed floating out) is needed.

Net ,or cage growing on is ok in a river situation as there is a constant water change going on but without an expensive (to buy and run)aeration system,in a pond situation the most economic way is to just let them go.Pond raising takes approx double the time that river cages do to attain 400 gram fish ,but margins are slimmer in river/cage rearing because of the intensive high protein feed required .

As RBH posted ,120cm is all the water depth you need as Pla Nin live 90% of their lives in the top 50cm of water.

After 7 years of crises including oxy depletion deaths,disease etc and lots of trial and error ,we find the best combination is 2000 fish per 1 raix120cm deep pond.

Most "expert" advise in tropical areas is only 800- 1000 fish per rai if raising to 800gram-1kg size.

Feeding Pla Nin any feed under 20% protein is considered a waste of money , experiments have shown that there is probably only a month difference in attaining a given weight using the green water method and no supplementary feed versus intensive feeding.

It is extremely hard to guesstimate the food requirements of Pla Nin as they have a two section stomach ,once the have taken in their fill into the first stomach section they just keep on eating ,but the excess food passes through without digestion , so your good money is turning to <deleted> with no benefit in terms of growth.

[nellyp]

Latest info is I think i've talked them out of Tilapia . I believe the oxygen aeration and water circulation problems to be too much for them. I also believe that they have no clue about Tilapia, the net is actually 5metres x 5 metres, they had not considered oxygen or waste build up . I know i probably know less than the family but I think they should start with something that will be a bit more managable. I am getting them to start with 200 catfish in the net along with another 100 in another net growing with 100 Tilapia of simular size. My hope is to grow them all in the nets. i will then (hopfully) be able to sell the 1st lot of catfish and release the tilapia into the pond to eat some algea (where is the spell checker on here) . Then buy more catfish for the second load. I am hoping that I can get around emptying the pond to remove the waste or at least wait until the pond is low enough in the dry season to make it more feasable and not interfere with using the water to water other projects we are trying. I have no clue if this will work but it will give us some experience. I will feed the catfish there own food in the nets along with the Tilapia. When the Tilapia are released I will give them different feed in the pond. I have been warned that the Tilapia may get tail rot with no circulation of water. This may seem a stupid question but would me fitting a pump to 4 inch pipe running from one side of the pond to the other and running it for a while every day help aerate the pond and do something towards circualation. i also need to figure something out about the waste as nobody seems to be worried about that on the farm. I have a picture in my head of sometime in the near future 200 catfish flopping about on a mound of their own <deleted> baking in the Sun, with my brother in-law scratchng his head at the side of it.

This kinda makes sense to me at the moment but will probably sound daft in the morning. Any thoughts on if this scenario would work as a learning tool would be appreciated....another long post.....I think I need more friends

Cheers

Neil

[RedBullHorn]

nellyp,the ordinary fine blue mesh hapa,s are not suitable for growing on Tilapia.

These are ok to rear to fingerling stage but then specially constructed (and expensive ) nets with at least a 1/2" mesh and preferably 1" with a band of fine mesh around the water line (to stop feed floating out) is needed.

Net ,or cage growing on is ok in a river situation as there is a constant water change going on but without an expensive (to buy and run)aeration system,in a pond situation the most economic way is to just let them go.Pond raising takes approx double the time that river cages do to attain 400 gram fish ,but margins are slimmer in river/cage rearing because of the intensive high protein feed required .

As RBH posted ,120cm is all the water depth you need as Pla Nin live 90% of their lives in the top 50cm of water.

After 7 years of crises including oxy depletion deaths,disease etc and lots of trial and error ,we find the best combination is 2000 fish per 1 raix120cm deep pond.

Most "expert" advise in tropical areas is only 800- 1000 fish per rai if raising to 800gram-1kg size.

Feeding Pla Nin any feed under 20% protein is considered a waste of money , experiments have shown that there is probably only a month difference in attaining a given weight using the green water method and no supplementary feed versus intensive feeding.

It is extremely hard to guesstimate the food requirements of Pla Nin as they have a two section stomach ,once the have taken in their fill into the first stomach section they just keep on eating ,but the excess food passes through without digestion , so your good money is turning to <deleted> with no benefit in terms of growth.

That's why i got out of tilapia business and stick to my Big Oui catfishes...1 rai 30'000 (thin) catfishes compare to 2'000 tilapia (thin down for ultimate result)...

catfish - 2 and a half months harvest compare to tilapia 6-8 months harvest...

by the way...just a tip...catfishes motality rate are higher in blue mesh hapa or net (35-50%)...good luck ~

Edited October 26, 2010 by RedBullHorn

[Sinblesser]

fitting a pump to 4 inch pipe running from one side of the pond to the other and running it for a while every day help aerate the pond and do something towards circualation.

A timer will save you heaps. Click here

Make sure the net ain't choked. Water always flows along the path of least resistance. Might wanna reconsider the standard blue net mate.

I've learnt a lot from this thread.

Cheers to all,

Sinblesser

p.s. Nelly, how about visiting a few fish farms first before making any significant changes? Get some insight.

[ozzydom]

nellyp, the rule of thumb when keeping tilapia in the blue mesh hapa,s is to scrub and clean the net once a week.A hose with decent pressure and a long handled scrubbing brush (plus elbow grease is all thats required. Alternatively ,a matching hapa placed adjacent to transfer the fish into while the dirty one is removed for on land cleaning,a couple of hours a week is all that is required.

A 6 outlet air pump will only cost you about 1200 baht and is suitable for a 5x5m hapa.

As stated previously ,these hapas are not suitable for growing on fish past fingerling stage.

All the Fisheries depots have people who will make hapas to order at pretty reasonable cost, a hapa with a larger mesh bottom (to let the poo fall through) could be used for growing on to a bigger stage,but stocking ratio must be kept low.

A pump to simply move water about is a waste of time unless it is fitted with a venturii to introduce air into the water stream,alternatively you need to get surface agitation to help aerate .

[nellyp]

fitting a pump to 4 inch pipe running from one side of the pond to the other and running it for a while every day help aerate the pond and do something towards circualation.

A timer will save you heaps. Click here

Make sure the net ain't choked. Water always flows along the path of least resistance. Might wanna reconsider the standard blue net mate.

I've learnt a lot from this thread.

Cheers to all,

Sinblesser

p.s. Nelly, how about visiting a few fish farms first before making any significant changes? Get some insight.

Yeah I'd love that but I don't know any....ahh well

[nellyp]

nellyp, the rule of thumb when keeping tilapia in the blue mesh hapa,s is to scrub and clean the net once a week.A hose with decent pressure and a long handled scrubbing brush (plus elbow grease is all thats required. Alternatively ,a matching hapa placed adjacent to transfer the fish into while the dirty one is removed for on land cleaning,a couple of hours a week is all that is required.

A 6 outlet air pump will only cost you about 1200 baht and is suitable for a 5x5m hapa.

As stated previously ,these hapas are not suitable for growing on fish past fingerling stage.

All the Fisheries depots have people who will make hapas to order at pretty reasonable cost, a hapa with a larger mesh bottom (to let the poo fall through) could be used for growing on to a bigger stage,but stocking ratio must be kept low.

A pump to simply move water about is a waste of time unless it is fitted with a venturii to introduce air into the water stream,alternatively you need to get surface agitation to help aerate .

I have decided not to worry about the Tilapia too much (just as an aid to getting rid of algae/waste). now you have blown my mind a bit though. If the poo collects in the mesh, then all I need to do is empty the poo out of the net after the fish have grown, or do I need to clean the net on a regular basis while the fish are growing????. As I have said i am now gonna concentrate on catfish, do you have any suggestions on a particular type, and how many can i grow in my little net. Also as far as I'm aware I do not have to worry so much about aeration with the catfish....is that correct??? and when you were talking about size of fish in the nets I tought you were only talking about Tilapia can the catfish stay in the net???

Sorry to be a pain.

Neil

[ozzydom]

nellyp, the rule of thumb when keeping tilapia in the blue mesh hapa,s is to scrub and clean the net once a week.A hose with decent pressure and a long handled scrubbing brush (plus elbow grease is all thats required. Alternatively ,a matching hapa placed adjacent to transfer the fish into while the dirty one is removed for on land cleaning,a couple of hours a week is all that is required.

A 6 outlet air pump will only cost you about 1200 baht and is suitable for a 5x5m hapa.

As stated previously ,these hapas are not suitable for growing on fish past fingerling stage.

All the Fisheries depots have people who will make hapas to order at pretty reasonable cost, a hapa with a larger mesh bottom (to let the poo fall through) could be used for growing on to a bigger stage,but stocking ratio must be kept low.

A pump to simply move water about is a waste of time unless it is fitted with a venturii to introduce air into the water stream,alternatively you need to get surface agitation to help aerate .

I have decided not to worry about the Tilapia too much (just as an aid to getting rid of algae/waste). now you have blown my mind a bit though. If the poo collects in the mesh, then all I need to do is empty the poo out of the net after the fish have grown, or do I need to clean the net on a regular basis while the fish are growing????. As I have said i am now gonna concentrate on catfish, do you have any suggestions on a particular type, and how many can i grow in my little net. Also as far as I'm aware I do not have to worry so much about aeration with the catfish....is that correct??? and when you were talking about size of fish in the nets I tought you were only talking about Tilapia can the catfish stay in the net???

Sorry to be a pain.

Neil

Neil, to grow virtually any fish on you will need a net with a bottom mesh big enough to let waste drop through but keep the fish in.

So first you need to grow the fry on to a size in a fine mesh hapa (cleaned regularly) that cannot pass through the particular bottom mesh in your growing on net , the sides need to be fine enough mesh to prevent food floating out.

If you are suspending the nets on bamboo poles or such ,it must be hung at a height that the net bottom is well clear of the pond bottom.

[Seanextra]

Hi , For aeration of water the use of Bubbles is not what airates the water as much as the action of the water being moved from the lower area of the vessel and introduced to the surface to make contact with the air, this is basically what air bubbles from airstones are doing circulating the lower water to the top and then the cycle of aeration is performed you can do this several ways some more effective than others and some more efficient . Air Bubble System using an air blower pump or smaller scale diaphram pump is genrally only used for indoor tanks and holding ponds it is not as efficent for large outdoor ponds and dams this is usually better done by a paddle airator. Pumping the water from a suspended pick up and blasting thru a wide jet on the surface is very effective and probably the best system to use but its expensive to run therefore not very practical, you can pump the water over a passage of rocks on the bank laid out over a pond liner in a spoon drain leading back into the pond or dam which will also eliminate alot of nitrogen and amonia build up using the good bacteria growing on the rocks but this system loses alot of water through evaporation must run continuos or with very little down time and so its not suitable for most low profit farms. If your able to turn water over by any means it will make a massive difference and it will reflect in your growth rates and genral health of the fish.

With regards to aquatic plants they do bring in high levels oxygen into the water but you need that many plants to do this in a pond or dam you wont have much room left for fish but everything helps and plants are prettty much free so if you go about combining a few different ideas you will see positive results. One farm i know in Queensland keeps their plants in netted off areas arounf the banks with smaller walls so they can be maintained when the main dam is drained for desilting and cleaning. the nets stop the fish from eating the plants and water quality is much improved, you can also use this method for growing duck weed to supliment the diets of omnivorus species by haveing a few netted off areas near banks with duckweed prootected from fish and then simply scooping out a few scoops to the fish and leaving enough to reproduce again floting weed is very good for extracting nitrogen but if its let go with also deplete oxygene thats why in the nets you have control over the weed.

there is alot more to this subject as you will find out but its not hard just takes time to get the feel for it.

Cheers

[IsaanAussie]

Seanextra,

Well presented post. I am building up my pond and it is hopefully going to be much as you describe. Currently I pump grey water from the pigs into the pond to fertilise it and use the same 3" sewage pump to aerate the "U" shaped pond. I place the pump at about 3/4 depth and the outlet hose end is positioned about 20 metres away broadcasting the lower water onto the surface. Very effective but with a 750W motor not ideal for costs as a permanent solution.

I have fountain bases in the pond and will use smaller submersible pumps set in the pond for each fountain. I will also set up a waterfall, in one corner of the pond with a similar pump driving that.

I dumped a small plastic bag of duckweed, that I borrowed from a local mechanic while his was fixing my car, into the pond and it is thriving.

Isaan Aussie

PS. If anyone is doing a similar thing, note, beware of the batch dosing rate of effluent you are using. Too must of a good thing is often too much for the fish. When I pump water in I then put the pump in the pond to mix and aerate as soon as possible.

[ozzydom]

There are a multitude of ways to try and maintain water quality,most have their upsides as well as their downsides.

Paddle aerators do a good job ,but are most suited to long reach ponds owing to the erosion factor,as well paddles only agitate the surface and do not bring up the lower water column.

If you set the paddles to deep much higher power requirements come into effect.

Paddles are most successful in shallow ,long reach ponds for higher value products such as prawns.

A similar effect can be attained using a pump with a spray bar.A 2"pump directed through a 2-3m pvc pipe with 1/8" nozzles set to contact the surface at about10-15 degrees works great with the advantage that the pickup can be drawing water from deep in the pond.

The disavantage is the capitol cost plus running costs as one or more unit is required for each pond and for low margin fin fish the costs outway the benefits.

To many surface plants can cause problems with shading,as well plants actually take oxygen from the water during darkness which is the critical period for oxygen depletion.

We have found(for our particular requirements) that a single 2.5hp blower which runs 50 x 4inch stons set at 3/4 water depth and caters for 5 rai of ponds at one time suits our needs ,both in performance and running cost.

We set our timer that they operate in a 2 hour on 2 hour off sequence between midnight and dawn and have had no problems since I installed the system.

[IsaanAussie]

There are a multitude of ways to try and maintain water quality,most have their upsides as well as their downsides.

Paddle aerators do a good job ,but are most suited to long reach ponds owing to the erosion factor,as well paddles only agitate the surface and do not bring up the lower water column.

If you set the paddles to deep much higher power requirements come into effect.

Paddles are most successful in shallow ,long reach ponds for higher value products such as prawns.

A similar effect can be attained using a pump with a spray bar.A 2"pump directed through a 2-3m pvc pipe with 1/8" nozzles set to contact the surface at about10-15 degrees works great with the advantage that the pickup can be drawing water from deep in the pond.

The disavantage is the capitol cost plus running costs as one or more unit is required for each pond and for low margin fin fish the costs outway the benefits.

To many surface plants can cause problems with shading,as well plants actually take oxygen from the water during darkness which is the critical period for oxygen depletion.

We have found(for our particular requirements) that a single 2.5hp blower which runs 50 x 4inch stons set at 3/4 water depth and caters for 5 rai of ponds at one time suits our needs ,both in performance and running cost.

We set our timer that they operate in a 2 hour on 2 hour off sequence between midnight and dawn and have had no problems since I installed the system.

As usual Oz, I'm all ears like a bag of wheat

[RedBullHorn]

There's a saying i know here...

Piggeries : Fruity and Issan Aussie

Tilapia : Ozzydom

Catfish : Me~

:lol:

[ozzydom]

Of course we could all be so fortunate as to be located at Kalasin ,where I had the good fortune to spend a day at a local prawn farm when I was considering delving into the crustaceans.

Thirty x1 rai ponds with no electricity, all the ponds were situated on a slope and water supplied from a large canal along the top of the hill.

When you want water you just open your inlet sluice and pay a token amount per hour that the inlet sluice is open, to empty the pond and harvest ,just put a catching net made out of the blue fine mesh on the outside of the drain pipe ,remove the plug and sit and watch the prawns roll in.(or is that out?)

Ring the Bangkok agent and that evening they roll up ,load the trucks and pay cash on the barrel head.

Running costs virtually nil and the whole place is run by the old man ,one son and one daughter.

The two earthen floored living quarters were squalid and I had mentally processed the figures as he had given me at between 4 and 5 mill baht a year income and was trying to get my head around living like that with that sort of income,when the daughter came up with a photo of their mansion in town and told us they only live like that at the farm for security .