Best way to line a pond?

   / Best way to line a pond? #21  
Clay has to be compacted to hold water. It also needs to be two feet thick to be effective. The easiest rule of thumb to see if it will work is to grab a handful of it when it's moist and squeeze it inot a ball inside your hand. If you can squeeze it tight and get it to stay firm and not fall apart, it will likely hold water.

Betonite is an additive that you add to clay. It is not waterpoof in itself. It does not compact. You have to have clay to use betonite. Then you spread it out, disk it in and compact it all together. What the Betonite does is swell once it gets wet, and that swelling helps to seal the clay that isn't doing the job. How much betonite depends on the quality of the clay. Mixing it and compacting it is critical, and if you don't do this properly, even the exact right amount of it for your soil wont help it hold water.

Good luck,
Eddie
 
   / Best way to line a pond?
  • Thread Starter
#22  
First thanks to everyone for all your help :thumbsup: We have done some more research, and it seems Bentonite is definately the way forward for us - if it wasn't for the responses on this thread I would never even have heard of it, as it is not commonly used here!

Luckily for us we have large deposits of Bentonite on our land (I had previosuly thought this was a shale rock) and in the surrounding area, so we should be relatively "self sufficient". Also some Spanish friends have access to an old quarry only a couple of miles away, which had large stock piles of Bentonite which has been dumped there following excavations in the area. Also this means that it is the best product to line our pond with, and we should even be able to complete the project far cheaper than we had planned. :)

Following Eddie's last post I have had a look at the different ways of applying Bentonite. Because of the rocky nature of the sub-soil at the depth we want to achieve, I am wary about mixing the bentonite into it. Instead we are going to use the "Blanket" method (Pond Sealer - Sodium Bentonite Pond Sealant - PDS Co., Inc.) - we will place a layer of compacted bentonite, followed by an equal layer of "puddled" topsoil (which as I said earlier is a light clay loam). We are now planning for the finnished pond to be about 50 metres by 20 metres - but will try a trial pond of just 5m square first to ensure the pland works :laughing: - I'll be sure to post some photos when we start work (probably later this month).

Now for my next question...

What is the best way to prevent a large pond from going green in a warm climate?

We will be installing a pump and fountain, and I am thinking maybe a reed bed? But would really like to here any tips / advice from other people who have already had to tackle the dreded Alage!!! I have started a new thread on this: http://www.tractorbynet.com/forums/projects/204898-how-stop-pond-going-green.html :thumbsup:
 
   / Best way to line a pond? #23  
First thanks to everyone for all your help :thumbsup: We have done some more research, and it seems Bentonite is definately the way forward for us - if it wasn't for the responses on this thread I would never even have heard of it, as it is not commonly used here!

Luckily for us we have large deposits of Bentonite on our land (I had previosuly thought this was a shale rock) and in the surrounding area, so we should be relatively "self sufficient". Also some Spanish friends have access to an old quarry only a couple of miles away, which had large stock piles of Bentonite which has been dumped there following excavations in the area. Also this means that it is the best product to line our pond with, and we should even be able to complete the project far cheaper than we had planned. :)

Following Eddie's last post I have had a look at the different ways of applying Bentonite. Because of the rocky nature of the sub-soil at the depth we want to achieve, I am wary about mixing the bentonite into it. Instead we are going to use the "Blanket" method (Pond Sealer - Sodium Bentonite Pond Sealant - PDS Co., Inc.) - we will place a layer of compacted bentonite, followed by an equal layer of "puddled" topsoil (which as I said earlier is a light clay loam). We are now planning for the finnished pond to be about 50 metres by 20 metres - but will try a trial pond of just 5m square first to ensure the pland works :laughing: - I'll be sure to post some photos when we start work (probably later this month).

Now for my next question...

What is the best way to prevent a large pond from going green in a warm climate?

We will be installing a pump and fountain, and I am thinking maybe a reed bed? But would really like to here any tips / advice from other people who have already had to tackle the dreded Alage!!! I have started a new thread on this: http://www.tractorbynet.com/forums/projects/204898-how-stop-pond-going-green.html :thumbsup:

Bentonite is a volcanic ash (In ex. mined in Wyoming). There are several types of it. Make sure that your is Sodium bentonite. It swells in presence of water about 20 times filling the crevices in surrounding material. To make it work it needs at least 30 cm of well compacted material on top of it. Normally it is applied in example by a fertilizer spreader and covered by whatever material available near by and compacted by driving at least wheeled tractor over it. Just to put some perspective on how much you need. I used 16 tons for 0.7 ac pond.
My pond used to drop about a foot in a day after the water level raised after heavy rain. It is still leaking but the rate is about an inch a week while the water level is about 6 ft higher. It seems to me the leakage is slowing down as the pond is aging. So I am hoping it will eventually stop.

Here is a link to great pond resource: http://forums.pondboss.com/ubbthreads.php
 
   / Best way to line a pond?
  • Thread Starter
#24  
Well the pond's coming on...

Having done lots of experiments with the bentonite around here, we found that it does indeed hold the water although there are quite a lot of impurities in it. Therefore we followed the advice posted here and put a thick layre of it covered by earth and tracked in with the machine. We have also then used a thick polythene liner as belt and braces - the idea being that the bentonite will seal any leaks as the develop. Aparently this is common practice in this area when resevoirs are built by the farmers.

I really wanted to avoid using polythene, but the size of the pond (it is much smaller than originally planned) and the shortage of natural water supply made it a logical thing to do (affordable without being too expensive). I know the pond is very VERY small compared to some (Eddie Walker!) but it'll suit our needs for the time being.

We have installed an experimental Reed Bed at the top end. I say experimental, as it is reverse flow - the water is pumped from the bottom end of the lake. It enters below the roots and filters up through stone, gravel and sand to the reeds. The idea is that this should both physically filter and purify (to some degree) the pond water.

Here is a video of it's development so far:
Duck Pond Project / Proyecto estanque de patos - YouTube

The next step is landscaping... watch this space.
 
   / Best way to line a pond? #25  
I am glad you succeeded. My pond is still leaking but despite that I saw it completely full due to very wet sprig this year.
As I read somewhere the liner will hold water but there is a tradeoff. Since it prevents mineral exchange you have to monitor water quality and treat it as needed.
 
   / Best way to line a pond? #26  
Nice to hear of your progress. Don't forget to post pics!!!

What's the old saying, it's not the size of your pond, but how you use it!!! :laughing:

Eddie
 
   / Best way to line a pond?
  • Thread Starter
#27  
Thanks guys - I will definately keep a close eye on water quality. Hopefully the Reed bed will help a bit - the idea is that water will be circulated through the bed at night (when electric is cheeper) and the sand & gravel will filter the water as well as the reeds providing oxygen. Also with the ducks, geese and fish, there will be quite a bit of you know what to feed the bacteria in the reed bed. Of course we will also plant lots of water plants...

The pond is approx 35m x 4m at it's widest - so a lot smaller than originally planned. However this may work in our favor as for much of the year evaporation will mean that it will need topping up regually. This will be done using the agricultural water, which comes from a mountain resivoir, so that should hopefully also help maintain water quality. We have also piped in our house guttering (and later will also connect the barn & stable gutering) so that when it does rain, it goes into the pond through the reed bed.

At the moment we are working laying a concrete rim to secure the top of the plastic and hold back the gravel / topsoil that we will use to landscape the banks. Obsticals I still have to overcome are to install an overflow across the track into the paddock (in case of heavy rain), and finding a way of controling mosquito larve next summer - I am hoping the carp will solve this problem for me, but am a bit concerned about the reed bed which is quite near the house...? Following the advice in earlier posts, I'm not going to worry too much about the water going green - if it does I will try the old barley straw trick and then worry if that doesn't work!

As requested Eddie, here are some pics. Unfotunately my camera stopped working so didn't get the early stages of the dig, but have got from when the liner went in onwards! There is also a short video if our geese and ducks trying the pond for the first time on youtube: Duck Pond Project / Proyecto estanque de patos - YouTube

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   / Best way to line a pond?
  • Thread Starter
#28  
   / Best way to line a pond?
  • Thread Starter
#29  
Here is an update of the pond - one year on....

 
   / Best way to line a pond? #30  
Great video. Nice to see it full of water and all the happy ducks swimming around!!! Congratulations.

Eddie
 
 
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