Looking for advice on sealing my pond: Liner vs. Sodium Bentonite?

[MoonShadows]

Your pond dig-out looks real nice...and you did it by hand! I could never imagine trying to do that here in northeast PA, our soil is so rocky.

We live on 15 acres. We have a small spring in a depression about 200 yards away from our house. When we first moved here, we planned to dam up one end and create a "natural" pond. The county and state paperwork and regulations were so outrageous, we abandoned the idea.

I would love to dig a big real pond in the back field, but the budget doesn't allow it.

This Spring I want to create a man-made pond in our immediate backyard that we can enjoy from the deck and when we are sitting down in the yard. I was thinking of going with a dug out one, but I think I am now moving more towards an raised one using an 8' diameter x 2' deep galvanized stock tank. It will hold about 700 gallons. I like the idea because it will be easier to do, easier to maintain, and lends to the "farm" look.

Here's the idea.

 

[SittinDuck]

Hello! I am new to ponds. Right now, it's just a hobby for me, but I love ponds. I have dug a small backyard pond (by hand!--whew!) and am looking for any advice from those experienced in digging and maintaining ponds. I have many questions and would love to chat...

I am including some pics of my pond as it is so far. And, I am wondering what is best way to seal it so it will hold water. Does anyone have any advice or info (especially experience) that you'd like to share? Much appreciated. Thanks!

Sealing that pond is easy! Simply fill it with water and walk around in it, stirring up as much clay as you can. Let the clay settle and walk some more. Keep doing that until it is sealed. Or you could throw some pigs in and let them do it.

 

[Thelone]

Hello! I am new to ponds. Right now, it's just a hobby for me, but I love ponds. I have dug a small backyard pond (by hand!--whew!) and am looking for any advice from those experienced in digging and maintaining ponds. I have many questions and would love to chat...

I am including some pics of my pond as it is so far. And, I am wondering what is best way to seal it so it will hold water. Does anyone have any advice or info (especially experience) that you'd like to share? Much appreciated. Thanks!

A great natural sealer is a soil with a high clay content. Ask at your local landscape supplier, depending on how much you want to throw into it. Maybe lay some hessian down for the clay to bind too then lay the clay soil about 2 inches (50mm) thick, you'll need to make it thicker in some place that are more vertical. (Maybe try and slope those sides that are more vertical a little bit.)

I would lay flat rocks over the clay to reduce the area plants can get a foot hold if you are using this for a fishy kind of water feature, these can be extended to form a border around the edge of your pond and would look good (to me any ways). I think your pond is a great shape and would lend itself well to this type of feature. My idea for not letting to many plants get a foot hold is so they don't 'choke' up the pond making it hard to see the aquatic life that is down there if that is what you are doing. If you go with flat rocks, try a variation in light and dark coloured rocks.

I've built large "turkey nests" or earthen tanks in country that would not hold the water, our solution was to cart soil in that had a high clay content, usually "black soil" as that stuff sticks to any thing! Where the flowed in from the well pump, we would lay rocks on top of hessian so the falling water would not "punch" through the black soil we had laid on the bottom. We usually covered the entire bottom and sides with the black clay soil about 6 inches or 15 cm deep. Some times it would take several months for the clay soils to seal the dams but once water plants started growing there they were usually good earth water tanks. These earthen tanks were fenced off from stock to stop cattle from ruining the sealing layer by way of heavy traffic in the dams or earth tanks. (We call them "Turkey nests" here in Australia.)

Leaves are already spilling into your pond so maybe some pruning or netting to keep it clean and as for algae, there a few snail species that will thrive on algae even in near freezing temperatures, most fish species require above 45 Fahrenheit to survive.

http://www.fishpondinfo.com/plants/algaetable.htm

 

[GodofPecking]

I'd use a plastic sheet for a hole like that, with soft soil or newspaper underneath. I wouldn't make it more permanent than that for at least a year, to see if it works in that position.

 

[Thelone]

I'd use a plastic sheet for a hole like that, with soft soil or newspaper underneath. I wouldn't make it more permanent than that for at least a year, to see if it works in that position.

Good advice!

 

[Fennel]

I was wondering if you actually built this pond? Do you have pictures? I'm considering something similar. I have a small farm, and will have room for maybe 15'x20', perhaps a bit bigger. Would like it to look natural, with big rocks and plants. Thinking about a little waterfall to keep water moving. What are you using for filtration? Did the bentonite/concrete combo work well? I have 7 ducks and 5 geese. It will be in full sun, but next to the woods. Will lily pads on the surface help prevent algae? We have the obnoxious kind of red clay here in KY. Thx.

I wanted a pond for many years, and am getting close to having one now. Here are my thoughts. I have seen small backyard ponds with a liner, and they are OK. They were generally shallow depressions dug about 2 feet deep in middle and tapered straight flat to edges. The liner stretched and looked smooth. Your dug out pond, ( beautiful by the way, shape ) is irregular. A liner placed into, would be with wrinkles. No liner made, comes with a forever life span. It would need to be replace within ??? years. Now lets look into sodium bentonite option. It is a great product , but may not be the best for your application. ( at least the way normally applied.) It will work great on large flat bottoms. It stays in a paste form and not solid. ( Read this in preventing ponds from leaking from cow hooves entering ponds to drink, etc.) I see 2 drawbacks here. First, it would be a challenge keeping it in place on the vertical walls of your pond. Second, it may prevent you from having nice clear water. The bentonite needs to be held in place with a layer of soil, sand, or whatever else. The way your pond is made suggests that you want to keep water plants and fish. If you were not thinking of fish??? then think again. The fish will naturally control the mosquitoes. Certain minnows are better at eating mosquito larvae than other fish. You experiment there for your best results. For fish, you need clear water, so you can enjoy seeing them, as well as for their well being. A small swimming pool type filtration and a means to aerate are also good for clear view pond water. Filtration does not need to run continuously. Aeration keeps water from going stagnant and developing unpleasant odors. You can do both as you see fit and best results.
Here are my plans on how I will make my pond. Mine will be about half the size of yours due to size of my yard. Not as deep ether. After I am finished digging, I will cover the soil with bentonite, about 2 inches. I will mix up small batches of cement and create a 1 inch thick cement layer. while cement is still not set, I will cover top with decorative river rock pebbles. I don't want the look of a sidewalk underwater. When cement hardens, I will remove all non binding pebbles and keep using them as I keep progressing with more cement troweling. Making cement mix stiff enough, I can apply vertically with limitations. This is more than a single afternoon project. When I have all cement completed, and one day hardened, then I will fill with water to cure cement. ( cement cures well when in water) Other option is to sprinkle with water often for at least the first week. I know there are cement sealers, that can be applied, but I personally will skip those, since I'm planning to keep fish. What I end up with is a thin shelled cement pond with pebbles on top. In time it will develop small cracks of course. That is the reason for the 2 inch layer of bentonite under cement. Water will stay clear not being clouded. The pebbles will keep the cracks out of sight also. It will have a natural look.
Every so often I will have to brush the sides and bottom with a broom to loosen up the green algae. The pool filter will remove all the floating particles as well as the algae.
Hope this gives you some possible ideas for your pond. AND

.

I wanted a pond for many years, and am getting close to having one now. Here are my thoughts. I have seen small backyard ponds with a liner, and they are OK. They were generally shallow depressions dug about 2 feet deep in middle and tapered straight flat to edges. The liner stretched and looked smooth. Your dug out pond, ( beautiful by the way, shape ) is irregular. A liner placed into, would be with wrinkles. No liner made, comes with a forever life span. It would need to be replace within ??? years. Now lets look into sodium bentonite option. It is a great product , but may not be the best for your application. ( at least the way normally applied.) It will work great on large flat bottoms. It stays in a paste form and not solid. ( Read this in preventing ponds from leaking from cow hooves entering ponds to drink, etc.) I see 2 drawbacks here. First, it would be a challenge keeping it in place on the vertical walls of your pond. Second, it may prevent you from having nice clear water. The bentonite needs to be held in place with a layer of soil, sand, or whatever else. The way your pond is made suggests that you want to keep water plants and fish. If you were not thinking of fish??? then think again. The fish will naturally control the mosquitoes. Certain minnows are better at eating mosquito larvae than other fish. You experiment there for your best results. For fish, you need clear water, so you can enjoy seeing them, as well as for their well being. A small swimming pool type filtration and a means to aerate are also good for clear view pond water. Filtration does not need to run continuously. Aeration keeps water from going stagnant and developing unpleasant odors. You can do both as you see fit and best results.
Here are my plans on how I will make my pond. Mine will be about half the size of yours due to size of my yard. Not as deep ether. After I am finished digging, I will cover the soil with bentonite, about 2 inches. I will mix up small batches of cement and create a 1 inch thick cement layer. while cement is still not set, I will cover top with decorative river rock pebbles. I don't want the look of a sidewalk underwater. When cement hardens, I will remove all non binding pebbles and keep using them as I keep progressing with more cement troweling. Making cement mix stiff enough, I can apply vertically with limitations. This is more than a single afternoon project. When I have all cement completed, and one day hardened, then I will fill with water to cure cement. ( cement cures well when in water) Other option is to sprinkle with water often for at least the first week. I know there are cement sealers, that can be applied, but I personally will skip those, since I'm planning to keep fish. What I end up with is a thin shelled cement pond with pebbles on top. In time it will develop small cracks of course. That is the reason for the 2 inch layer of bentonite under cement. Water will stay clear not being clouded. The pebbles will keep the cracks out of sight also. It will have a natural look.
Every so often I will have to brush the sides and bottom with a broom to loosen up the green algae. The pool filter will remove all the floating particles as well as the algae.
Hope this gives you some possible ideas for your pond. AND

.

 

[Fennel]

I found this article that sounds similar:
http://www.hyperbrain.me/build-natural-pond/

 

[fishpondcoating]

Pond sealer is to seal the leakage in pond and pond liner. For instant and long lasting results Pond sealer by Pondpro2000 is the most effective way.