Lining A Pond With Plastic

[Smithson]

We have a pond, roughly 5m x 15 and would like to line it with plastic. I've found a shop selling the liner (2.2m x .25m x50m for B4,300), they also sell a glue for joining. Does this price sound OK The plastic seems strong. Is it thick enough and would it be safe for fish we plan on eating?

I'd like opinions on how to go about lining it. I was thinking to wait till the dry season, when the pond is almost empty, then do it, but am not sure how. Should put sand on the bottom? We will raise fish for eating, but would also like the pond to look really nice. Can I put a ring of concrete with stones and bricks around the top? I've seen this done on very small ponds.

Any help is much appreciated.

[ozzydom]

You only need about 1.5 m water depth so here is how I would go about it.

Wait until the dry season ,pump the pond out and dig a sump in the deepest point to get as much water as possible out, then let it dry out.

Using plastic sheeting you need a good thickness of sifted sand (a foot deep) compacted in the bottom as one sharp stone left under the liner and you will have a hole.

I would make the sides vertical as erosion will not be a factor.

If you have a large enough area to pre glue the sections (the local freeway) you could prefab 4 lengths about 20m long ,that would cover the base and both ends in one go and giving a decent section to lay up the sides .

You should then only need a single width to over lap your side turnup.

I would definately go with your idea of a concrete plinth around the top ,higher than the surrounding ground to keep out run-off and debris.You can make it decorative in various ways.

After installation I would put about 6 inches of washed sand in the bottom before filling.

Cannot see any problem growing fish in it and if looks are important I would consider a swimming pool sand filter run a few hours a day.This can be reverse flushed onto a garden area to provide fertilizer.

Barramundi could be kept in this type of pond. Nam Sai Farm supplies Barra fry trained to feed on floating feed.

[enjoyinglife2]

Hi,

Contact these people www.sumanahg.com I think they will have everything you need plus heaps of great advise.

[Smithson]

Nam Sai Farm supplies Barra fry trained to feed on floating feed.

How do the train such small fish?

At present the pond is about 3m deep, I'd like to keep this depth. Ideally I'd like a large aquaponics system. My dream is to have a nice looking pond stocked with fish. Rather than a filter, I'd run it all up to a sort of terraced garden with vegies. The water would flow back to the pond. As it passed our house there would be a small stream and finally a waterfall into the pond. I could also incorporate another pond at the top of the system with a different variety of fish.

Does this sound doable?

[ozzydom]

Nam Sai Farm supplies Barra fry trained to feed on floating feed.

How do the train such small fish?

With lots of patience,in their indoor recirculating tanks, a worker sits there and sprinkles small food (similar to aquarium food)for the swim up fry to rise to and eat , they soon seem to get the idea. The barra,s I put in have grown about 100gram per month on pellets.

At present the pond is about 3m deep, I'd like to keep this depth. Ideally I'd like a large aquaponics system. My dream is to have a nice looking pond stocked with fish. Rather than a filter, I'd run it all up to a sort of terraced garden with vegies. The water would flow back to the pond. As it passed our house there would be a small stream and finally a waterfall into the pond. I could also incorporate another pond at the top of the system with a different variety of fish.

Does this sound doable?

If you can keep the water reasonably clear 3m is ok but if it is cloudy or full of suspended clay then light will not penetrate and the bottom ends up a smelly mess.

Depending on the topography of your land ,your plan is "doable", If you run the water back through an excavated Klong you are going to end up with muddy water ,a contoured rill section ,concreted like a spoon drain and provided with river stones and sharp sand would aerate the water as would a waterfall .

Initial and ongoing costs would be high because you have to get the water to the highest point of the project to make any of it work so it would require ,I guess a high volume/low pressure pumping system of some description.

If you get the levels right and the elevations are not very great maybe you could incorporate a paddle wheel in the pond to be driven by the waterfall.

[Smithson]

If the water was pumped from the bottom, then the problems you mention wouldn't be so great, correct?

There is a slight slope, but not great. Any idea what a pump would cost?

We plan on having our house overlook the pond, there are mountains a few 100 meters away.

Set up and operating costs would be high, but it would provide all food needs and some left over to sell. Of course it may not be a good ROI, but would provide a lovely living environment without having to spend time and money going out to buy food.

[ozzydom]

If the water was pumped from the bottom, then the problems you mention wouldn't be so great, correct?

There is a slight slope, but not great. Any idea what a pump would cost?

We plan on having our house overlook the pond, there are mountains a few 100 meters away.

Set up and operating costs would be high, but it would provide all food needs and some left over to sell. Of course it may not be a good ROI, but would provide a lovely living environment without having to spend time and money going out to buy food.

If you mean from the bottom of the pond (3m), not a good idea unless you were pumping to a filter of some type as this water would be rank with ammonia from the rubbish ,fish excreta , rotting vegatation etc, at 3m the water is usually to dark to allow the micro-organisms that break down this gunk to flourish.

If the creek section you plan has plenty of round stone and sharp sand and is almost level so that the flow only meanders along ,this would help in filtration.

The pump required would depend on what you envisage the end result to look like in terms of size,flow , etc . Anything up to a 10 inch with power at 1 hp per inch.

If the creek section back to the pond were near level and you put in a small dam with a spillway to give the waterfall effect a 4 inch would probably give enough flow to just get water movement. If you are looking for a mountain stream effect you need a very large capacity pump.

One I did many years ago was with a channel about 6 feet wide ,the channel was done with freestone concreted into the bottom and sides ,the dam(spillway) backed the water up to about 75cm deep , The pump was timed to run 2x 4hr phases every 24 hours and was a 6inch.

Landscaped and feature lit ,it came up well as a garden setting, complete with Japanese walk-over, but it still cost the surgeon client a few brain operations.

[Smithson]

If you mean from the bottom of the pond (3m), not a good idea unless you were pumping to a filter of some type as this water would be rank with ammonia from the rubbish ,fish excreta , rotting vegatation etc, at 3m the water is usually to dark to allow the micro-organisms that break down this gunk to flourish.

The grow section of an aquaponics system has all the micro-organisms to break the gunk down, from ammonia, to nitrate and finally nitrite. Although I tend to think 2m would be enough depth.

[basilic13]

Hi Smithson,

could you please let me know where you bought your liner for the pond? do you have the company's website?

Thanks!