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Spin

So the 10,000 is the profit, right? 100,000 to 200,000 a year from three fairly small tanks.
This might be something I'd like to have a crack at, I certainly have the free time.

tsicar

trying to find the site on the net that got me going. will give you an idea of what it entails and how it is done. i will post here when i find it. from one of the south african universities, but am having difficulty findin it right now.

mellow

tsicar, you wrote that the tanks were of poor design for water exchange. I do not understand this , because such circular tanks with the center standpipe, seems to be very popular and highly recommended by all the fish farming info on RAS.
I would agree that the Bio filter which he had was lacking in that he didn't have a bottom drain on it, in order to get rid of dead bacteria, or any other solids which may accumulate at the bottom. After I spoke to him about it he added some (one in each tower). Please explain why you feel that the superchargers weren't supplying enough dissolved oxygen.
The nitrite and Ammonia levels could of been dealt with by adding a simple foam fractioner.

mellow

Not disputing anything, just gleaning thoughts on the subject.

tsicar

ok, here goes:

his tanks worked on an overflow system, meaning all the shit accumulated at the BOTTOM of the tanks, instead of exiting at the bottom as it would have had he used an external, swivelling upstand pipe.
he ended up drilling some small holes in the bottom, which was not enough, got clogged easily, and if his inflow varied (which it did sometimes) his tanks either emptied (which they did,killing the fish.) or overflowed (which they did.)

the filters were trickle-tower. these are a good system, but rely on a trickle of water running through a medium, (he used knotted canvas strapping as media)exposing the aerobic bacteria to oxygen and thus allowing them to do their job. his problem was that there was not enough flow for the amount of fish he was trying to rear.
had he increased the flow-through, the filter would not have worked efficiently.
he would have needed at least another six towers to give him the necessary flow through at his tanks, which is exactly why i am not a big fan of trickle tower.
i calculated his flow-through at the tanks and i pointed out he was doing a water change only every 5 or 6 hours, but he insisted i was wrong. even catfish want a complete change about every hour.

had he had more towers, he wouild not have needed extra oxygenation, since the tower would have oxygenated the water sufficiently.
he contacted me by email on a few occasions, before i ever met him, explaining that he was losing large amounts of fish, and i told him the reason. i suggested he add salt to the water (tilapia can live at high salinity, unlike catfish, and salt helps with the nitrites), and this he did, but he had the idea that he could run with high oxygen levels, a high ph and too high nitrites. he bragged that he could get away with the toxic nitrite levels because of the high ph.well, this has a little truth in it, but actually, there are two kinds of amonias , one more toxic than the other, and at high ph levels, there is a higher concentration of the toxic one.

anybody who has raised aquarium fish or koi seriously, can tell you that 90% of oxygenation will occur at the surface. far less is to be gained using an airstone than by vigorously disturbing the surface. most of the oxygen an airstone will put in the water is at the point that the small bubbles burst on the surface.
he could have saved all that electricity just by raising the level and angle of his inlet pipe. i noticed the mistake first time i saw his system, and asked him by how much the airstones had increased his DO and he said he had not checked.
his electricity bill was somwhere around 40000baht per month, and his turnover was nowhere near that, so it was all just a matter of time.

making your own fishfood is not for ameteurs. dalton had no way of checking if his feed was adequate for his fish, nutrition wise, and he relied instead on a formula he got from a program he downloaded off the internet.
he did not know that the soya needs to be heated to over 100 degrees celsius for an hour in order for its protien to be accessible, and would not listen when i told him, instead telling me that the feed was "cooked in the extrusion process (where some, but not enough heat is produced), or it would not float"
i remember him posting on this forum about his fish not growing, attracting a lot of advice from various posters, from myself included, but we all assumed that his feed was ok, which it was NOT.
he said that it was the cold weather (IN BURRIRAM IN JUNE????)

so here's what went wrong:

inadequate filtration, wrong infrastructure, inadequate nutrition, totally inefficient us of energy and labour, inadequate monitoring of water quality, no record keeping, and a thai attitude to learning.

tsicar

i was really hoping that this would not become a "have a go at dalton" thread, since i really liked the guy, both as a poster and as a human being, but there is a lot at stake for people who may sink money into an operation that will bring no return, or fail because of incorrect advice, so i guess it had to come out, eventually.
my conciense has been bugging me every time i saw the exchanges on the forum between dalton and mellow, and i have bitten my tongue till now, but since dalton seems to have left the forum, and since i don't think he will come back to thailand (DEFINITELY NOT TO FISHFARM), I feel relieved to have been able to release this information.
if anybody wants to do this type of aquaculture and succeed, they have to know that there is ONLY ONE WAY to do it, and if all the factors are not taken into account, the result will be failure.
ALL the info is available on the internet (an whole lot of misinformation, too), and all the processes, especially with regard to producing catfish in an extreme high density environment have been tested and documented, and studied and perfected by universities all over the world, information having
been shared between them for decades.
it is highly unlikely that you, or dalton, or myself will come up with a miraculous discovery, or be able to come up with an idea to circumvent the science that has been applied and proven and still be able to come up a winner.

remember that what the thai universities put out for aquaculturists has all had to be adapted and made suitable for the kind of person, and the education level of the likely thai fishfarmer, and although they (the university proifessors and aquaculture departments),
probably DO know what has to be known and are technologically aware of these processes, they have probably not released the information, because it would cause more chaos than another military coup in thailand, so what you will get in thailand is info to help a subsistence farmer earn a small living or produce a bit of protien for the family without getting confused or investing too much money.
do NOT follow any thai advice if you are looking for anything more than what i have just described.

mellow

^ To discuss a couple of points that you made:
I agree that a separate up stand pipe to discharge accumelated waste from the bottom of the tank is a welcome idea and should be used. The pipe does not have to be external. It can be located within the tank. A lot of waste does however overflow with the single pipe.
Trickle Towers are a good and inexpensive system, he had 4 towers with 3inch outlets. On gravity flow this could equal to 480gpm. If he would of had twice as many towers for 34 tanks, I believe he would have been alright. Serious modification of the settling tank could quite possibly have aleviated a lot of the problem too. There was no way to clean it out, without emptying the entire mechanical filtration tank. It was also quite a bit lower then his tanks and therefore prone to overflow. The media baskets he had put in there, once clogged up with sediment would considerably slow down the water flow comming from the tanks, causing them to overflow. I saw no by-pass to allow the system to keep running, during the clean out process. An extreme hasle in all aspects I believe when needing done. A complete water change every 2 hours could also be adequate.
Oxygenation:The wife and I ran an experiment with 2 small RAS's wich used Trickle towers, and although they were about 20% in size of all the combined tanks in the unit, extra oxygenation was still needed, or the fish were gulping air on the surface. We ran stocked at 60 to 70%. The outlet pipe from the Bio to the tanks also had pipes going up, to alow air into and out of the delivery line. All Aquaculture operations I have read about or seen, employ added oxygenation. I am however looking for a way not too.
I am certainly not having a go a Dalton who has always been cordial to both my wife and I. He has allowed me to visit a number of times to check out his farm. There I learned quite a lot, both from going all over the place to check out the systems themselves, and answering my questions. I hope he makes it back and is successfull. It is a good example to discuss though, because we have seen it, and it was operational, to an extend only Dalton knows for sure. Too bad he is no longer participating here. The list of do's and don'ts would be interesting.

tsicar

if the upstand pipe is located outside of the tank, with it's inlet at the lowest level of a sloped tank floor, the waste accumulating at the bottom of the slope virtually gets sucked out when the pipe overflows, which is all the time that the water flows into the tank from the filter, plus the outlet pipe can be swivelled to adjust water level, and emptying of the tank to harvest or for maintenance is easy.
dalton was having to use a submersible pump to empty his tanks every time someone came to buy fish, (electricity, time, labour.............)

tsicar

ok, i found this one which gives a good overview of how it all works, and whether you would think it worthwhile.have not read it all over again but i seem to remember there is a good section on polyculture, too.
just google: "the biology and culture of the african catfish"
there are a few more really interesting ones, which are better for beginners, and if anybody wants ne to recommend, i will, but this one needs to be read first.

tsicar

yes, your tilapia may need oxygen, but there are far better ways to provide it than with airstones. since you are recirculating anyway, i should think you could add oxygen for free, as you have done with your venturi system, or by allowing the inlet to fall and splash the surface. a spray from the pump into the tower instead of a flow, a paddlewheel powered off the incoming water ,etc will also help. using a supercharger and an airstone is just plain stupidity.

mellow

If your drainage pipe is within the tank, you need a larger outside pipe and a smaller inner one with slots, or holes in it. You then pull on the outer bigger pipe, and the sediment likewise gets sucked out. It is then ejected out of the system directly. The tank can then be topped off, and also have a partial water change.

tsicar

i think you misunderstand, mellow.
the external pipe IS the overflow, and since you are recirculating water, the outflow is continuous, but the water "overflows" from the bottom, not the surface of the water, at the same rate as your inflow. not only for draining the sediment, but continuous outflow of heavier particles (solids) which naturally collect nearer the bottom of the tank and fouls the water.

mellow

^ link please.

tsicar

unfortunately i do not have a link for it, but i made mine like this (i think i posted this before here somewhere):

my tanks were rectangular, and if you want a circular tank you would be better off drawing from the centre of the tank.

slightly sloping tank floor , with your drain at the lowest point. i use 4inch blue pvc for the entire thing, and you will need to make a small sump with a removable plastic grate to prevent escapees, mine were those plastic baskets you can get at the talaat: they come in different mesh sizes so you can upgrede larger as your fish grow.
outet runs to just past the edge of your tank, then a 90 degree coupling, NOT cemented to the drainpipe, so that it can be swivelled upwards or downwards.
to the bend, add a pipe as high as the depth of your tank.
now you can swivel the pipe down to adjust depth of water in the tank. the pipe will maintain the water in the tank since the tank and upstand pipe will always have the same water level.
do not worry about the swiveljoint coming undone -you may find it gets too tight, in which case you can sand the pipe down a bit to free it. i added a system using a spring to retain the joint, but it is not necessary.

mellow

Sorry , I am having a hard time visualizing how your system works. No problem imagining the pipe you describe, but visualizing how your water circulates in the system. A few pictures would certainly help. You said you did'nt invent any of this, therefore the info came from somewhere. I have not run across this, although I have been reading about it for a dozen years or more. Interesting.

tsicar

ok i found a diagram of the upstand pipe on that site i recommended for spin. just click on the highlighted UPSTAND PIPE in the section on pond construction and you will find it.
http://cdserver2.ru.ac.za/cd/catfish/catfish/cat82a.htm

i constructed my tanks with this system before i found the info on the net, so i made a few mistakes, my tanks were too large for catfish they should be 2mx1mx1m. the water simply flows in at one end and out at the bottom of the other end of the tank through the upstand, falling (and adding some oxygen) into a drainage ditch then back to the filter.
the upstand can be used on circular tanks or ponds too.
the pics i found on that site they seem to be using 50mm pipe but the 4inch works better.

mellow

This explains nothing. For all purposes the label concrete sump, can simply be replaced to read filter. It would then be a normal stand pipe in any system, with water going to a filter.

tsicar

no, the small sump i made was just to house the plastic basket to prevent the fish going out of the drain. it is not really necessary- the point is that the solids laden water exits from where it collects, at the bottom of the tank, instead of remailing inside the tank as in the popular thai overflow pipe system, where you would have to manually drain it from the bottom of the tank, by removing the upstand pipe for a while.
it is still an overflow system, but takes the water from the bottom of the tank.
if you take a glass of water and mix some dirt into it, you will find that the dirt slowly sinks to the bottom. now if you trickle clean water into the top of the glass until it overflows and gives you a water exchange in one hour, you will notice that most of the dirt stays at the bottom, and mostly clean water only overflows, as it does in an upstand overflow system. syphon the water from the bottom, and the solids exit, as they would in a swivelling external upstand system which takes the water from the bottom of the tank.

i used this system for the inlet, too, since it was easy to adjust the swivel pipe to give the exact flow i needed. i could let it fill a bucket of known volume while timing it, then calculate and adjust the exact amount of water going into the tank in an hour.

mellow

^ Sound's like the hard way of doing it, and it doesn't eliminate the sediment from the system, cause its going to your filters, our gets taken out from the system, on its own discharge line. Never even makes to the filter.

tsicar

takes the sediment out of the tanks with no input from labour., then goes to the settlement then a system of rocks stones and baffles for anaerobic conversion of solid waste,with a bottom drain on this tank for easy occasional cleaning, then only onto the biofilter for aerobic conversion clean water to tanks. no shit in the biofilter. no shit in the tanks and full anaerobic conversion of solids. almost no water is lost, almost no shit remains in the rearing tank and biomedia does not get clogged with crap. totally labour and energy efficient.
or you can do it the easy way, where you have to periodically climb into the rearing tank to pull out the pipe to get the sediment and dead fish out because you did not get the water exchange you needed (most of the clean water from the filter overflowed down the upstand and all the solids remained in your tank- try the experiment with the glass of dirty water which i suggested earlier) )and the solids stayed in the rearing tank, rotted and drove the ammonia levels sky high, which is what killed dalton's fish before they got to growout. as the fish grew, the larger ones died off until nitrite levels stabilised enough for deaths to cease, then they grew again, needed more feed, produced more nitrite, died off, etc.