I have noticed that in SA koi keepers seem to opt for the more traditional pond construction of concrete, bricks and mortar. In other countries the liner option seems very popular.
Cost-wise liners seem to be very feasible @ R40 - R50. The basic cost of 5x3x2 pond (liner 10x8m) can cost less than R4000 - for a 30000 l pond.
Vastly improved HDPE products as opposed to 'old PVC'
No leaks that 'patch & solution' can't fix.
Bottom drains (110mm) with a flange are available.
Dig a hole, fix in bidum lining, drop in a liner and fill with water. Add fish. All in a few days DIY.

One concern: How does one retain a close to vertical side without problems of possible inward collapse?

I am on the verge of building my second pond, and am seriously considering this as an alternative to concrete.

Any comments / suggestions would be appreciated.

Regards
Jack

Sorry..meant LDPE - not HDPE.

Hi Jack
Ek het geen ondervinding van Liner damme nie, en het slegs meer vrae as enige antwoorde.
My vraag is egter hoekom baie van die liners damme nog steeds met 'n struktuur selfs met stene gebou voor liner ingesit word?
Is dit moonlik om liner sonder kreukels en voue in te sit indien daar slegs 'n gat gegrawe word?
Hoe word die sludge wat opbou tussen kreukels en voue verwyder in formele tuin dam?
Ek sien daar word ook baie damme gebou met een of ander soort van hitte beskerming tussen dam en liner?

Hi Jack

I stood next to a 8000Lt liner pond a few days ago, it was very professionally done and one could not even see that it was a liner pond.
This one however was made by aquatan and the walls was like 3 to 4 mm thick. a skimmer, mid level inlet, bottom drain, the whole tootie, was welded.

I think the water weight on the inside will resist external pressure to a large extent, unless of course your soil is very unstable.

Apparently they took the dimension to them and actually waited for the pond to be completed, took it home followed the procedures and voila.

Now this is some expert advice and I will forward my invoice.

Hi Bobby,

Ek dink die eenigste rede hoekom daar eers gebou word sal seker maar wees omdat die grond in die omgewing onstabiel sou wees.

Die kreukels en voue, wel ek glo nie dit is regtig n probleem nie die water massa druk dit redelik stewig vas. n mens moet seker maar hier n bietjie die
instaleerder aanspreek.

Die underfelt word geinstalleer om te help dat klippies nie die liner beskadig nie.

Die aquatan dam sal nie kreukels maak nie maar hy is bietjie duurder.

PS ek is nou nie heeltemal seker van hul naam spelling maar hulle is in midrand.

Jack Bach wrote:

One concern: How does one retain a close to vertical side without problems of possible inward collapse?
Regards
Jack

Pond 1

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On this pond, I have build a frame with wood and levelled it. I then did a box with hardboard attached to the frame, no bottom. As I filled with water, I supported the hardboad on the outer side with a sand/cement mixture to prevent it from being pushed out by the pressure of the water filling. After I filled the pond, I sprayed the sand/cement mixture on the outer side with water to let it cure. I then placed a deck over the edges to ensure that the sun does not ruin the liner which would have been exposed to the sun all the time.

Pond 2

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On this one, I layed concrete lintels around the top edges of the hole and added 50cm x 50 cm cement pavers to the top. The liner went in between the lintel frame and pavers.

The pavers prevented rain water from entering between the soil and liner, thereby preventing the pond edges to collapse.

I should have let the pavers overhang a bit to prevent the sun from ruining the liner exposed to the sun. The liner above water level perished after three years due to sun exposure.

Hi Paul
Ek kan die 'images' nie oop maak nie. Sal graag wil sien.
Wanneer het jy die liner geinstalleer? Jy verwys na 2 jaar en die gedeelte bo die wateroppervlak het geperish. Is die plastiek tegnologie deesdae nie meer gevorderd nie. UV resistant ens. Ek het Chris N se dam gesien en ek dink dit was 'n liner pond. Baie, baie netjies, en regop kante. Amper nie eers voue gesien nie, maar hy het plante wat oor die kante rank tot amper op watervlak.
Groete
Jack

OK Paul. Sien nou die images. Sal Neville se bril moet leen.

Jack Bach wrote:

Is die plastiek tegnologie deesdae nie meer gevorderd nie. UV resistant ens. Jack

Jy sal sien ek het my post verander na 3 jaar nadat ek 'n paar berekeninge gemaak het.

Ja, jy kry UV bestande liners, maar hulle is heelwat duurder, en omdat die liners swart is, word hulle vrek warm bo die watervlak. Selfs die UV bestande liners gee in na 'n paar jaar. Van my groot 100 000 liter liner ponds op die plaas is al vodde na 'n jaar.

Dit is uiters belangrik dat jy skadu skep om die blootgestelde liner te beskerm.

Hi Neville.
I managed to find Aquatan's website, and posted my query there. Let's see what their response is. I've also asked about degradation of the liner above water level (Paul's concern). By the way they're based in Isando, not Midrand...AND DEFINITELY NOT KRUGERSDORP. (Based on yesterday's post elsewhere on the Forum).
You mentioned an Aquatan 'instant pond' earlier. Where is the pond now? I would like to see it "in operation".
Groete
Jack

Hi Jack

Maar hulle is darem nie te ver van ons ne nader as die Kaap.

Jack hierdie ouens se liner is vir n baie lang tyd gewaarborg.

ek stuur vir jou n PM met die mense se addres ok wil nie dit sommer hier plaas nie. Netnou gaan die hele Koi bedryf soontoe.
Ag jammer oor waar hulle is ek het so lekker met die dame gesels nie juis oor pond liners en goed geworry nie man.

Hi Neville
Alles is nader as die Kaap....Currie Cup, Super14, Vodacom Cup...
Dankie vir die terugvoer.

Een van die dae gaan julle nog mooi vra vir visums vir die vooreg om die Kaap te mag besoek.

How to manage "above water level" degradation of liner.
In my follow-up I came across a UK publication, which has the following idea:
Since it is my intention to have the pond raised approx. 400mm above ground level, build a 9" (double row) brick retaining wall. Just above the foundation for this wall the liner is folded to first run horizontally under the inner first row of bricks, and then vertically between the two rows of bricks to the top row, and then folded over to the outside. Finish top with coping / paving blocks. The wall can be plastered and / or tiled. The liner remains an intact waterproofing medium, and is not exposed to the elements.

The book I saw this in is "A Practical Guide to Building and Maintaining a Koi Pond" by Keith Holmes and Tony Pitham. p. 45

Hi Jack

Although today's liners are made from very good materials the south African sun is not your playmate.

I have also seen that method and it does make a lot of sense, I would put that into my plans if your pond was going to get full sun and no plants. Remember it is mainly our afternoon sun that is the bad boy.