Fish Farming - Paddle Wheel Aerators

[David48]

Fish Farming - Paddle Wheel Aerators

Just thought I'd share how the Thai's aerate their ponds.

All very simple stuff ... just like Thai Farming in general.

Questions, as always are welcomed.

It's a series of YouTubes because sometimes they speak 10,000 words.

The first in the series ...

So, it's your bog standard Paddle Wheel Aerator.

What is of note, apart to introduce the subject is the length of the drive shaft ... that run is about 40 metres ... yep ... 40 metres!

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[BookMan]

Does that move around to different locations in the fish pond or is it fixed?

[cooked]

It would get nicked inside of a week around here. Irrigating rice means someone has to sleep with the pump.

All the same we are thinking of Plaa nin for next year, so maybe we'll be taking it in turns to sleep out there with the Phi.

Thanks for the interesting link.

[Payboy]

So, it's your bog standard Paddle Wheel Aerator.

Not this patented one?

http://www.chaipat.or.th/chaipat_old/journal/aug03/aerator_e.html

[David48]

@ Payboy ... yes, I know that one well , but seems to be in use for other then aerating Fish Ponds.

@ BookMan ... definitely fixed ... the pump shed can be seen in the distance. Fixed insomuch that it's rigid.

I like this one remembering the Seagulls at the MCG.

Those are bamboo poles that are embedded in the pond floor can be removed that assembly dismantled.

... I thought I had a photo of them resting on the ground once the pond had been drained ... but can't locate that at the moment.

@ cooked ... yep ... the digs do vary ... but they ALL sleep next to their investment.

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[David48]

Most (if not all) are powered by big bore, single pot motors

Inside one of the sheds

I'll do a separate thread on Farm Machinery that is used on the Farm.

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[David48]

Never surprised with the simplicity of how Thai solve problems.

The prop shaft is simply welded galv tubing

The bearing being simply no more then a greased wooden stake in the ground.

Most have the clamping rope tie.

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[David48]

Using an old cheap car diff to change the direction of drive

... or splitting the drive, (just as in a car diff driving the wheels) between 2 ponds.

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[shaggy1969]

A simple but very effective set up there at the farm David.

That is probably the longest drive shaft ever made, 40 meters and straight as a die.........Impressive !!!

[Dancealot]

Wonderful you took the time to document this. I understand their main function is to oxygenise the pond?

[David48]

Wonderful you took the time to document this. I understand their main function is to oxygenise the pond?

Thanks for asking about the Aerators.

If you are interested in aerating your pond or interested in how they work ... the full answer is here in post #27 from the Fish and Shrimp Farm thread.

Lots of good information contained in there.

Also is the explanation of Thermal Stratification in post #23

Essentially the purpose of the Thai style Aeration is to mix up the layers that form in a pond (below)

by adding oxygen (above)

... without stirring up the bottom mud layer.

All the good stuff is in Posts 23 and 27.

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[Packdee]

This machine is also very good for fish farming.

It can take water out of the pond until the last drop.

[David48]

Khun Packdee, thank you for posting above.

I know that machine as the Farm's neighbour has one, but it's the other side of the Klong and I have not seen it so close to see it.

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[David48]

If you look at post #8 above again, the 2 Video (#8999) and it's amazing to me how he achieves the drive system.

For those interested, I've drawn it here ... Paddle Wheel aerators Layout.doc

The central drive shaft running the Aerators at the end of the pond.

Keeping it simple.

[Naam]

big thanks David for an extremely interesting contribution! a pity that the usual resident Thai bashers ("Thais are lazy, dumb and non-innovative") will never look into a thread like this.

[slapout]

One thing I have noticed about farmers, if they are long term at it, they can impervise, modify, adaprt, what they have avaliable to make their work eaiser, faster, more economical and then they will help their friends to follow suit. Its amazing the little tweeks/improvements made after a walk around, a few cold brewskies, a few 'it might, won't, will work' comments.

These are the type of people (farmers) who know they have to listen to the old timers and the old timers know they have to listen to the young bucks.to stay at their chosen profession.

[David48]

Gets a bit blurry at the end ... no need to adjust your glasses) ...

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[David48]

Just a side on shot showing how they work.

An overview of the pond showing how they run 4 Aerators off one motor in 2 different ponds from 1 motor ... pretty cool if you ask me!

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[David48]

With kind permission from RedBullHorn, here is his personal solution which differs from what you can buy commercially.

1. home made aerator at start up LOW speed

2. home made aerator at start up LOW speed

1 of 3

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[David48]

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3. homemade aerator at MEDIUM speed

4. homemade aerator at MAX speed part 1

2 of 3

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[David48]

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5. homemade aerator at MAX speed part 2

3 of 3

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[David48]

That's sort of it for this thread from me for the moment.

I've got more media of the Paddlewheels ... but you've seen one, you've seen them all.

Same but different little bit.

Good though to repost from an earlier thread I wrote about Thermal/Oxygen Stratification ... one of the main reasons that you Aerate the Ponds ...

BELOW

Thermal/Oxygen Stratification

Even though the illustration below talks about a ‘summer kill’, it is in reality what

happens in a pond on a daily basis.



The upper layer where the fish feed closest to the ponds surface is oxygen rich.
However, the lower strata, where the prawns feed starts to become oxygen deprived.



How quickly the oxygen is depleted is dependant upon a number of variables,
salinity, surface temperature, stocking and feeding rate, rainfall etc.
But the #1 reason is the simple lack of wind. The wind repletes the oxygen
and if it’s strong enough can mix the stratas a little.


What surprised me when I first started researching this and asking questions

why the gf’s parents did such and such was how quickly the oxygen level drops.



Above is a chart which reflects this. Of course it’s for a still day when
there is no oxygen being replaced to the waters surface. The chart is
slightly wrong when compared to other research read because the low
point in the oxygen cycle occurs about an hour before dawn.

I thought this fish farming was a bit of a lark but it’s not unlike many
other animal farms and in a similar vein to dairy farms … it’s up before
dawn to check the levels and start the aerators if required.

Remember this is Thailand and they don’t use a fancy machine to estimate the
dissolved oxygen saturation so I am told “it’s a feeling thing David”.



Above is a good example of the stratification that occurs with both the water

temperature and the dissolved oxygen.

What happens when you get it wrong?

Well, judging by what happened a few months ago … the prawns are the first to suffer.

Yep, the reason that we had the feast of those blue coloured prawns , is that they

actually either died and floated to the surface or simply crawled out of the pond … and died.

Still tasty though!

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Edited June 1, 2013 by David48

[David48]

There is quite a bit of information around about windmill powered
aerators and with a good wind I’m sure they do a good job of supplying
oxygen to the pond.

But if you have a good wind … you don’t need a lot of aeration!

For the hobby farmer with low stocking rates, aeration is not a big deal.

But for the Thai Farmer who could lose a considerable proportion of his/her
livelihood in a day, or more likely overnight ... it's vital.


Mississippi State University based literature, still easily read.
http://www.thefishsi...9/pond-aeration

More serious and for the technically minded
http://www.fao.org/d...4E/x5744e0m.htm

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[RedBullHorn]

With kind permission from RedBullHorn, here is his personal solution which differs from what you can buy commercially.

1. home made aerator at start up LOW speed

2. home made aerator at start up LOW speed

1 of 3

.

The home-made aerator units are for my neighbour, building a set at his request, upon satisfaction, the whole set up was sold for an agreed price of ฿5'000 plus 2 bottles of Lao Khao.

Clarias catfish doesn't require regularly paddle wheels aeration because they have seperate organ for breathing beside breathing through their gills.

Edited June 2, 2013 by RedBullHorn