Clay To Seal A Fish Pond

[billd766]

I have a fishpond about 45 x 15 metres in area ranging from about 1 metre at the shallow part and nearly 3 metres at the deepest.

My problem has been that over a 3 to 6 month period it seems to have less water than my neighbours on either side so I suspect that I have a leak somewhere.

I have read somewhere that a pond can be sealed by clay so that it doesn't leak.

However I have no idea what kind of clay I would need, how much in quantity, how much in price or even where to find any.

I did look on Google but the couple of Thai companies I found didn't respond to emails and when I called them nobody could speak English and had no idea what I was talking about.

Can anybody help me please?

[Maizefarmer]

Ponds side by side tend to establish equlibrium - of course the distance between them is a factor and you don't say how far apart they are spread (?)

R U sure it ain't leaking through the floor of the pond - in either case its a fair amount of clay that will be needed unless you can of course id exactly where the leak is.

Any dense clay should do the job, but plastic lining may well be an easier applied alternative (?).

[billd766]

Ponds side by side tend to establish equlibrium - of course the distance between them is a factor and you don't say how far apart they are spread (?)

R U sure it ain't leaking through the floor of the pond - in either case its a fair amount of clay that will be needed unless you can of course id exactly where the leak is.

Any dense clay should do the job, but plastic lining may well be an easier applied alternative (?).

Sadly I have only the one pond as we live on the side of a hill and the depth of soil is not so much before I run into rock.

We have asked around the village but unfortunately on our side of the road nobody has managed to successfully did a borehole.

There is a klong opposite that I used to get water from sometimes but that involved laying a pipe down the side of our land, under the neighbours drive, across the front of his land though on the government land outside of the power poles, through the drainpipe under the road, across somebody elses land.

A total of about 350 metres of piping and I only used 1 1/4 flexi pipe for most of it. Also it had to raise the water about 10 metres vertically as well.

I used a Chinese made "Honda" water pump and whilst I got the water up to the tanks and fish pond the was not a lot of pressure at the far end.

Last year I bought a 1300 litre water tank that fitted on my pick up and shuttled water from 3km farther back along the klong but I could only manage a maximun of 7 runs a day.

I was 63 then (65 now) and it knackered me plus the cost of diesel for the truck and gasoline for the pump cost a fiar bit.

As a comparison the rough costs per cubic metre were as follows

village water = 3 baht

pumped from the klong = 20 baht

shuttled from the klong = 24 baht

bought from the water tanker (from a different klong) = 50 baht

I the rainy season I can use the village water but not really in the dry season as it has to do all the village and not just my fish pond.

[Gary A]

There is a product called bentonite that is sometimes used to seal leaky ponds. I have no idea what it costs in bulk but you could likely get information from a foundry. The material is also used for making molds for casting. I think it is also a major component of cat litter. The material itself is a mix of mostly clay that swells when wet. I remember the foundry bought it in one ton bags.

[Maizefarmer]

Bentonite, Gary - excellent stuff, but on the scale the Op is wanting to do it on, me thinks the cost would be prohibitive. Now that billd766 has laid out the detail a bit more, I am even more inclide to think that a plastic lining is his only viable option.

Billd766 - nice to see someone who has got to grips with the cost of moving water - its what I'm afraid a lot of folk don't do in Thailand, and moving water, wheather its through a sprinkler (always the most expensive), through a long pipe, up a hill ... or whatever, is always least expensive at low flow & pressure rates - and using ac electricity - think you could get that down to around Baht 10 p/cube (meter) - but as I said, it will be a low flow rate (meaning: what you are now moving over say a couple hours will take maybe 6 -7hrs. Still, if collectively, that is sufficient on a daily, or whatever basis, it would be worth doing, wouldn't it?

[Boksida]

There is a product called bentonite that is sometimes used to seal leaky ponds. I have no idea what it costs in bulk but you could likely get information from a foundry. The material is also used for making molds for casting. I think it is also a major component of cat litter. The material itself is a mix of mostly clay that swells when wet. I remember the foundry bought it in one ton bags.

Drilling grade bentonite is 8 baht/kilo from Thai Nippon Chemical. They have a website. There have also been several previous threads on bentonite which may have further information.

[billd766]

Bentonite, Gary - excellent stuff, but on the scale the Op is wanting to do it on, me thinks the cost would be prohibitive. Now that billd766 has laid out the detail a bit more, I am even more inclide to think that a plastic lining is his only viable option.

Billd766 - nice to see someone who has got to grips with the cost of moving water - its what I'm afraid a lot of folk don't do in Thailand, and moving water, wheather its through a sprinkler (always the most expensive), through a long pipe, up a hill ... or whatever, is always least expensive at low flow & pressure rates - and using ac electricity - think you could get that down to around Baht 10 p/cube (meter) - but as I said, it will be a low flow rate (meaning: what you are now moving over say a couple hours will take maybe 6 -7hrs. Still, if collectively, that is sufficient on a daily, or whatever basis, it would be worth doing, wouldn't it?

I have been trying to work out the evaporation rate and after guesswork and a few american websites the best I can guess is around 5 cu/m per 24 hours.

Assuming that the neighbours are agreeable to me running the pipes I went to my local hardware shop this morning and got some prices of 2 inch blue pvc stuff and a guesstimate for a biggish water pump. She had a 2 hp motor that takes 8 amps at a steady rate which is about 2 kw or 2 units of electricity and will pump 500 litres per hour at the pump head.

1 unit of electricity will cost me about 4 baht so to run that pump will cost about 8 baht an hour or 16 baht per cu/mt.

A bigger pump will be more efficient but cost more to run.

I have also tried to work out the volume of water and its weight in a 2 inch pipe 350 metres long which is pi Rsquared times the height or distance but the figures look wrong as I end up with 55 somethings using 50mm as the r2 and 350m as the height.

The original outlay for the pipes etc I have done a small spreadsheet and over a long term it seems feasable but it will be a bugger of a job top do.

I will have to glue the pipes and trench them in on my land and possibly in front of next doors property and through the drainpipe under the road and the power cable 2.5 sq/mm will be in the same trench.

On the far side of the road as that person will not allow me to bury the pipe I will put a male and female connector on each 4 metre length of pipe and screww them together for easy removal when required.

The power cable will be broken on the far side of the drainpipe and set as high as possible for safety during the wet season in a waterproof box. The next run of cable will be done in yellow 1/2 inch pipe with a male/female connection for easy dismantling.

The pump will need to be put in some sort of ventilated and drainable container with a circuit breaker at each end for the power.

The water pipe will have a one way valve close to the pump to stop the water flowing back into the klong.

water_pipe_prices.xls

From Boksida

Drilling grade bentonite is 8 baht/kilo from Thai Nippon Chemical. They have a website. There have also been several previous threads on bentonite which may have further information.

I did try them but I didn't get much sense from them probably due to my bad Thai and nobody I spoke to could speak English.

As they are based close to Bankok the transport costs will be quite high and nobody around here seems to have worked with clay.

There was a guy on TV called Somtham who rarely posts now. I went to see him several years ago and he was saying that he used clay but tamped it down by tractor which is OK if you have a flat bottomed pond. Unfortunately mine isn't.

[WatersEdge]

As mentioned above, Bentonite is good but expensive in the drilling mud / foundry mold / oil filter bagged form.

I work in Mae Sot and have fumbled upon a huge supply of extremely fine grained blue grey clay,

in some patches it is light brown to red with grey streaks, even multicolored in the same strata

sometimes with coal seams scattered above it

Which as near as I can tell short of expensive lab analysis, is native Calcium Bentonite.

It is hard with wide cracks when dry,

wets to pliable, then wets further to a sticky grease,

and more still to a liquid slurry.

It is dug by track hoe and dump truck in the dry season,

used by the thousands of loads as common lot fill.

My trucker friend says we cannot idly move clay among the provinces

without government documentation, but that's a clerical barrier.

I used it to seal a pond, 9 loads @ 15 tons => 135 tons

and because it was cheap and abundant,

I spared nothing and applied it deep,

even using it as grade filler in the uneven pond bottom.

I read that you are supposed to till it into the existing pond bottom,

but I just dumped it over the surface.

As it comes off the trucks, it has large clumps down to fine dirt

and when you dump them in the water they melt and slump.

Because it is so dense and clumpy,

it requires a lot of labor to apply

During Rainy season now, they have stopped digging at the pit,

but probably will start again when the rain stops.

I ran a test, hammer milling dry clods to dust.

It grinds very quickly, as only the physical bonds between particles are broken,

not any structure of the material itself

It grinds fine during dry season after open sun drying,

but would not be workable during rainy season.

as it absorbs moisture aggressively and sticks to everything

Once in a feed bag, it remains powder until it contacts water.

Over the course of time in moist air,

the bags develop a light crust as moisture penetrates the bag wall.

The trucks haul 15 ton on a ten wheel, and 30 ton on truck and trailer

It seems for as many Fish Pond owners as we have on the farm forum,

there is a decent volume need for it.

Would anyone like to volunteer to look after government documentation,

transporting 30 ton loads of as mined dirt,

from Tak province to any other province in the land?

The trucks stand ready waiting for dry weather.

[billd766]

In my first picture that rock was the biggest that they could get out of the hole and if I remember it was about 1.5 x 1.0 x 0.5 metres.

In the second picture the guy digging the pond suggested we leave that one alone unless we wanted to either use a pneumatic/hydraulic pick on the digger or drill and dynamite it.

Either way we may crack the rock underneath so we left it there.

There is only about 1/2 metre of water at the deepest part now and the rest is dry and even has trees growing in it as I have been working offshore and my wife isn't too bothered about it.

I would like to sort it all out, clean it up and put enough fish in it to sell a few and keep my wifes shop stocked for cooking and selling on.

Purely as a hobby for me.

Regarding the post by Watersedge I could be interested but I live about 200km from MaeSot and I suspect the transport costs would be high to ship it that distance.

[Maizefarmer]

billd766

The weight of the water should not be an issue: using a large diameter pipe to reduce friction losses is always a good idea on long run with limited pump power, but at the start and the end of the run you can insert a "choke" - effectively a reducer, which will off-set the weight in the large diameter run to that consistant with the diameter of the choke. Weight is static - its backpressure and nothing more, and proportional to the surface area.

So don;t let the water weight compound the calc's for you.

If you share with me your ideal flow rate and the actual rise, I'll be happy to reply with a power/ setup opinion - and for what it worth, pumps/irrigation/hydraulics (fluid dynamics) is actually my speciality within ag engineering - ironically, although I've done a lot of courses and attended a lot of tarining modules over the years, I never actually trained as a dairy farmer (thats all self taught over the last 2 decades).

[slapout]

A friend of mine had a pond which was leaking. He drained it and while still fairly wet , spread cotton seed hulls, then covered this with a thin layer of bentonite. He used a tired roller to pack this down. Besides stopping the leak, the water clarity was improved. He, as a oiley, had access to both items and probably at a discounted price thru volume price.

[basilic13]

Hi Maizefarmer,

you mentioned above using plastic liner for the pond.

Would you know what kind of product exactly to use and where to get it? I have been looking around here and on internet, and I can't find product and company names for this.

Thanks

[Maizefarmer]

I'll do some research for you - most large decent hradare stores have plastic for pond lining and going in with your Thai partner (who no doubt understands what you are trying to achieve) will be sufficient to get the message across.

The problem is you get plastic and you get plastic - some of it is real crap stuff and some of it is good stuff - and , yup you guessed right - the good stuff can be real expensive. I know some stuff that comes in at Baht 4K per 50meter x 2meter (wide) roll - it need to be ultrasonically welded - but its real good stuff (no ways you'd be able to tear it by hand).

It comes down to how how you are willing to pay, but my experiance is this: so long as the base is smooth the plastic well laid out and well overlapped, then a good top cover of fine soil put over it (to prevent punctures), you can achieve a fairly decent and very long lasting seal.

An alternative is to throw a concreate base - idealy reinforced, but not neccessarily so.

In any event - either way requires the pond having to be drained, and the issue you have here is that your pond is full of water. I prseume if need be you would drain it (?)

[basilic13]

Maizefarmer very interesting thanks.

The pond (recreational, about 800 m2) is going to be made in 2 weeks, so obviously any prior advice would be most welcome and highly appreciated! Cost is obviously an issue, but also simplicity as I have no experience in the field at all (and to what extent it can be made in a DIY way)

I don't know yet whether after the digging there will be water in it at all. I kind of hope so, as I am presuming that no lining would be required if the water level is high enough. Would you agree?

As for the draining of the water if the water level is too low and we need lining, I didn't even think of it! So thanks for bringing that up!

Another question I had, was: would it make sense to dig the pond first, and in case of no or insufficient water, to do the lining at a much later stage (as this would be getting more complicated). In effect, we would have an empty and "dry" whole for some time. We could already plant on the banks to consolidate them, but would it get much damaged with the passing of some time (rain, wind,...)?

Many thanks!

[Maizefarmer]

Aaaah - its not made yet: then your best bet by far has to be level out the base, then tamping it down real firm and throwing a couple inches of concreate with 4" x 4" reinforcing mesh. That is by far the best way to seal a pond - and as youre only throwing a skin so to speak, the volume isn't all that much - but prep work is very important.

[littlebigboss]

Have you considered that maybe it's not a problem of leaking ? We have several ponds and the ones that leak are dry a few weeks after the end of the rainy season, but you're talking of 3 to 6 months.

Then among the ponds that keep water until the end of the dry season, the level may vary from pond to pond, but I believe the difference is more the access to some underground water source than a leak.

[Maizefarmer]

5tons of water a day from a surface area that large sounds a lot, but is very relaistic - if I recall correctly it;s around 10 tons of water per 24hrs from an acre of corn field!

10 000litres of water every day from every acre of corn field - more than a pure 100% water layer?

Yes - Why? - because the surface tension of pure water is significantly higher than that of damp soil, and the surface area of a pond exposed to evapouration is significantly less than that of a field of corn of the same flat square meterage.

[billd766]

billd766

The weight of the water should not be an issue: using a large diameter pipe to reduce friction losses is always a good idea on long run with limited pump power, but at the start and the end of the run you can insert a "choke" - effectively a reducer, which will off-set the weight in the large diameter run to that consistant with the diameter of the choke. Weight is static - its backpressure and nothing more, and proportional to the surface area.

So don;t let the water weight compound the calc's for you.

If you share with me your ideal flow rate and the actual rise, I'll be happy to reply with a power/ setup opinion - and for what it worth, pumps/irrigation/hydraulics (fluid dynamics) is actually my speciality within ag engineering - ironically, although I've done a lot of courses and attended a lot of tarining modules over the years, I never actually trained as a dairy farmer (thats all self taught over the last 2 decades).

Hi Maizefarmer

Sorry for the delay in answering but we have had some friends over from the UK that we haven't seen for over 5 years and catching up and partying took precedence over TV.

My plan is to run a thick 2 inch blue pvc pipe from the klong to my fishpond.

It will rise around 2 metres from the klong using a flexible 2 inch hose to reach the electric pump.

The next section will be about 120 metres using the same thick 2 inch pipe and male/female connectors in more or less a straight line to the drainpipe under the road. This land belongs to another person and I am sure that I have permission to lay the pipe across her land and it will mainly be in the part that the flood water has washed away anyway. The m/f connectors are for easy dismantling of the pipe during the wet season. I am also going to put a blanking point in to the pipe at the drainpipe end so that when the system is shut down no creepy crawlies, bugs or rats can move in and make a home there.

From that point it is a 40 metre run of pipe and I will make 2 x 45 degree bends with a short pipe in the middle of them.

Another 50 metre straight run rising another 2 metres across my next door neighbours land but on the government side and then across his drive and I will sink it in a trench anyway.

2 more 45 deg bends onto my land and another 2 metre rise over 75 metres followed by another 2 x 45 bend to run alongside the fishpond where I will put a T piece with 1 leg going into the pond and the other leg running a further 50 metres to my water storage tanks.

There are 20 "ongs" each holding 1500 litres of water form the time when we had 12 people on site and no government water for a couple of months during the dry season.

I am planning to use a 5hp electic motor with a rated capacity of 500 litres per minute at the pump output but what I will get at the far end I have no idea. The cable will be 2 x2.5 sq/mm and at the pump end I have worke out that I will drop about 6 volts. There will be a circuit breaker at each end of the cable and at the point where the cable comes out at the road drainpipe I plan to raise that to well above the rain flood level and put in a waterproof plug and socket so that it can be dismantled easily as well. All the power cables will be in pvc pipes and the pump will be put into a large plastic box with ventilation holes to keep the rain off it.

I will also put in a 1 way valve close to the pump plus a tap to shut the water off and keep it in the pipe when the pump is not running.

I have a future plan of a sort of small market garden which no doubt will need irrigation and my wife is on about keeping chickens and ducks.

I have reduced some photos of the pond in its current state and I will clear all the trees out before filling the pond.

As you can see it is not really possible to put a PVC liner into the pond as it is too uneven.

[laser]

I am also in the process of digging a pond. We started early this year but after getting down 2-3 mtrs everything came to a halt, because of the same rock (boulder) problems as you. I decided to put everything on hold and see if the unfinished pond would hold water and same as you it will not.

Once I come up with an idea and remove the rocks (boulders) i will spread Bentonite throughout.

I know from experience if the Bentonite is spread properly it works 95% of the time.

David

[billd766]

I am also in the process of digging a pond. We started early this year but after getting down 2-3 mtrs everything came to a halt, because of the same rock (boulder) problems as you. I decided to put everything on hold and see if the unfinished pond would hold water and same as you it will not.

Once I come up with an idea and remove the rocks (boulders) i will spread Bentonite throughout.

I know from experience if the Bentonite is spread properly it works 95% of the time.

David

Hi laser

I hope that you are lucky and end up with a fairly flat bottom and easy sloping sides.

You say from experience that Bentonite is good 95% of the time.

Was that you doing it yourself in Thailand or an experienced work crew.

Every day I am out the front of the house with a petrol strimmer with the rotary saw blade clearing away the scrub and brush from the last 18 months. It varies from 50cm grass and weeds up to nearly 3 metres with trees and rocks hiding in it.

After 2 hours I am trashed for the day.

Granted that I am 65, retired and fat and I am doing it now while I am still capable as in a few years I will not be able to.

It is a form of exercise and also of will power and I will be damned if so piddly area of ground will beat me though in truth it is more like 2,500 sq/m.

:D

[littlebigboss]

Every day I am out the front of the house with a petrol strimmer with the rotary saw blade clearing away the scrub and brush from the last 18 months. It varies from 50cm grass and weeds up to nearly 3 metres with trees and rocks hiding in it.

After 2 hours I am trashed for the day.

Granted that I am 65, retired and fat and I am doing it now while I am still capable as in a few years I will not be able to.

It is a form of exercise and also of will power and I will be damned if so piddly area of ground will beat me though in truth it is more like 2,500 sq/m.

I definitely agree with you, I'm a bit younger and only slightly overweight (ok, my wife will argue with the "slightly" ), but I did similar exercise for the past two weeks, around 4 to 6 hours a day, and I lost 3 Kg !!!! Believe me, I now feel really bad to be seated in my nice climatised office !

[laser]

billd,

My father dug a pond some years back in the USA, and the pond would not hold water to the level we wanted. Being in the oil drilling business he came across some mentonite from a friend and spread throughout the pond, by sprinkling over the water and shovel fulls along the sides. The pond has been full of water for years and only rises and declines with the weather. Friends and faming spread the bentonite over a two day period. (Free BBQ & Beer)

He shared his sucess with others in the area and they also met with sucess.

[billd766]

billd,

My father dug a pond some years back in the USA, and the pond would not hold water to the level we wanted. Being in the oil drilling business he came across some mentonite from a friend and spread throughout the pond, by sprinkling over the water and shovel fulls along the sides. The pond has been full of water for years and only rises and declines with the weather. Friends and faming spread the bentonite over a two day period. (Free BBQ & Beer)

He shared his sucess with others in the area and they also met with sucess.

The main problem I see with with Bentonite is that I will have to buy it from somewhere, get it shipped up to where I live and get some local guys to spread it and it should be OK.

However I have talked to Watersedge above about the stuff he can get in Mae Sot.

That would be 900 -1,000 baht a truck load plus 5,000 baht per truck delivery.

Once I have put my initial piping in then which I need to do anyway I figure it will cost me around 10 baht an hour to pump perhaps 2 cu/mt or maybe 30 baht a day. If I compare that to 6,000 baht a truck load then it becomes a cost issue as I will get evaporation and have to top up the pond anyway.

Thanks for the information though.

It seems as though I have to really think this through instead of going at it half-assed as I did in the beginning.