I have a concrete-lined pond, figure-8 shaped, approx 15' x 5' x 30" deep,
inherited when I moved in 18 months ago. It looks quite old, has mature
Koi, a crazy-paving edging, and very mature plants around it (7' Pampas
Grass x 3, plus great clumps of Kniphoria, Bergenia and Gardener's Garters)
.. It looks fantastic, the frogs adore it, but it has a significant leak. I
this suspect may be caused by the now huge rootballs of the Pampas Grass
which are about a foot away from the pond edge (no evidence for this - just
a hunch. I can't actually get under the Pampas Grass to find out - they are
so big and position is almost inaccessible sandwiched between a fence and
the pond edge. There is no obvious leak visible, no hole or crack to be
seen, but I must now have a hose running constantly, I guess 0.25
gallon/hour, day and night, which clearly can't continue.

Does anyone have any experience of such a situation?
The way I see it, the options are
1) Drain the pond, apply new skim of cement or flexible sealant to the
existing surface
2) Drain, then fit a pond liner into the nice neat hole
3) Re-shape the hole and fit a pre-formed pond

1) is possible, but the same problem could arise again in a year or two
2) sounds better but I am worried about placing liner in a cement-lined
hole. I once saw rain get between liner and the wall of the pond. This was
a new pond dug into very heavy clay soil. Water ran in during heavy rain,
causing the liner to separate from the pond wall. It forced pond water over
the edge of the pond, putting even more water into the cavity between liner
and the clay. This caused the liner to rise more, until it and the material
lining the pond were floating happily on the surface, with all the water
UNDER the pond liner. Don't laugh - I saw it happen!
3) I don't think I'd find a pre-formed pond to the size I want, so this
sounds like too much disruption

Has anyone any practical experience of repairing a concrete pond?
Particularly 1) or 2)?
Baz

2) Drain, then fit a pond liner into the nice neat hole
2) sounds better but I am worried about placing liner in a cement-lined
hole. I once saw rain get between liner and the wall of the pond.

The best solution would be to fix the leak, but how you go about finding the
leak I haven't got a clue.

Having said that though, I remember the local water authority used to put
fluroscene die (not sure on the spelling) into water to trace leaks. It is
an
extremely strong die, just a teaspoon full would colour an entire Olympic
sized swimming pool! I don't think it is toxic - but I'd check before using
it anywhere near Koi! Just a small amount of it in water turns it into a
blue/green colour. It is then a case of looking for the coloured water.
Perhaps a few small bore holes at strategic places around the pond?

Perhaps this technique could be put into reverse? If you completely drained
the pond and put died water all around it, you may get tell tale marks
appearing as the water/die leaked INTO the pond?

I agree with you on point 2. When I had a slow leak in an old liner I went
out to get a
replacement and had the intention of placing the new one in the old one.
Luckily I bought the liner from an aquatic centre with experts at hand. They
told me NOT to do that otherwise I'd just end up with a waterbed as water
got between the two liners and forced them apart. However, I could put the
new liner into the old provided I slashed plenty of holes in the old liner.
In your case I guess this would mean smashing the bottom of the existing
pond in a number of places to ensure free drainage. It should then be
possible to put a new liner in.

--
Drakanthus.


(Spam filter: Include the word VB anywhere in the subject line or emails
will never reach me.)

2) Drain, then fit a pond liner into the nice neat hole
2) sounds better but I am worried about placing liner in a cement-lined
hole. I once saw rain get between liner and the wall of the pond.

The best solution would be to fix the leak, but how you go about finding the
leak I haven't got a clue.

Having said that though, I remember the local water authority used to put
fluroscene die (not sure on the spelling) into water to trace leaks. It is
an
extremely strong die, just a teaspoon full would colour an entire Olympic
sized swimming pool! I don't think it is toxic - but I'd check before using
it anywhere near Koi! Just a small amount of it in water turns it into a
blue/green colour. It is then a case of looking for the coloured water.
Perhaps a few small bore holes at strategic places around the pond?

Perhaps this technique could be put into reverse? If you completely drained
the pond and put died water all around it, you may get tell tale marks
appearing as the water/die leaked INTO the pond?

I agree with you on point 2. When I had a slow leak in an old liner I went
out to get a
replacement and had the intention of placing the new one in the old one.
Luckily I bought the liner from an aquatic centre with experts at hand. They
told me NOT to do that otherwise I'd just end up with a waterbed as water
got between the two liners and forced them apart. However, I could put the
new liner into the old provided I slashed plenty of holes in the old liner.
In your case I guess this would mean smashing the bottom of the existing
pond in a number of places to ensure free drainage. It should then be
possible to put a new liner in.

--
Drakanthus.


(Spam filter: Include the word VB anywhere in the subject line or emails
will never reach me.)

In article ,
Drakanthus writes
The best solution would be to fix the leak, but how you go about finding the
leak I haven't got a clue.

Having said that though, I remember the local water authority used to put
fluroscene die (not sure on the spelling) into water to trace leaks. It is
an
extremely strong die, just a teaspoon full would colour an entire Olympic
sized swimming pool! I don't think it is toxic - but I'd check before using
it anywhere near Koi!

Do check - but it should be OK - AFAIK it's used in caving, to decide
where a disappearing stream resurfaces, and cavers are pretty concerned
about the environment.
--
Kay Easton

Edward's earthworm page:
http://www.scarboro.demon.co.uk/edward/index.htm

"Drakanthus" wrote in message
...
2) Drain, then fit a pond liner into the nice neat hole
2) sounds better but I am worried about placing liner in a cement-lined
hole. I once saw rain get between liner and the wall of the pond.

The best solution would be to fix the leak, but how you go about finding
the
leak I haven't got a clue.

If the hole is in the side of the pond and you stop refilling it, the water
level should settle just below the leak. Then you can look around the pond
just above the water surface.

This is what I had to do with my pond last year.

If all the water drains out, then you know you've got a hole in the bottom.
So make sure you keep an eye on it as it's draining and remove any fish if
it gets too low.

BTW if the hole is in the bottom of the pond then dying the water isn't
going show up, unless you dig under the pond.

HTH

Cheers

Nick

If the hole is in the side of the pond and you stop refilling it, the
water
level should settle just below the leak. Then you can look around the pond
just above the water surface.

Nick


When my pond liner had a slow leak a couple of years ago I tried that but
just couldn't see it anywhere. Trouble with a slow leak is that you only
need the smallest pin prick to lose the water and finding it is nigh on
impossible. I think my mistake was buying a cheap polythene liner from B&Q.
It came tightly folded in a bag - the corners looked overstretched, plus it
was very thin and flimsy. I ended up replacing it with a better quality
liner cut off the roll from a reputable aquarist. Since then I've also set
up a second pond and used Butyl - much better quality, strong and flexible.
I understand it is also repairable - if you can find the leak :-)

--
Drakanthus.


(Spam filter: Include the word VB anywhere in the subject line or emails
will never reach me.)

Go to this link:
http://www.winsfordwalledgarden.free...tStructs/Ciste
rns/Cistern.htm

and click on the cistern repair link in the fourth paragraph.

Regards,
Mike Gilmore
www.winsfordwalledgarden.freeserve.co.uk


"Barry Watts" wrote in message
...
I have a concrete-lined pond, figure-8 shaped, approx 15' x 5' x 30" deep,
inherited when I moved in 18 months ago. It looks quite old, has mature
Koi, a crazy-paving edging, and very mature plants around it (7' Pampas
Grass x 3, plus great clumps of Kniphoria, Bergenia and Gardener's
Garters)
. It looks fantastic, the frogs adore it, but it has a significant leak.
I
this suspect may be caused by the now huge rootballs of the Pampas Grass
which are about a foot away from the pond edge (no evidence for this -
just
a hunch. I can't actually get under the Pampas Grass to find out - they
are
so big and position is almost inaccessible sandwiched between a fence and
the pond edge. There is no obvious leak visible, no hole or crack to be
seen, but I must now have a hose running constantly, I guess 0.25
gallon/hour, day and night, which clearly can't continue.

Does anyone have any experience of such a situation?
The way I see it, the options are
1) Drain the pond, apply new skim of cement or flexible sealant to the
existing surface
2) Drain, then fit a pond liner into the nice neat hole
3) Re-shape the hole and fit a pre-formed pond

1) is possible, but the same problem could arise again in a year or two
2) sounds better but I am worried about placing liner in a cement-lined
hole. I once saw rain get between liner and the wall of the pond. This
was
a new pond dug into very heavy clay soil. Water ran in during heavy rain,
causing the liner to separate from the pond wall. It forced pond water
over
the edge of the pond, putting even more water into the cavity between
liner
and the clay. This caused the liner to rise more, until it and the
material
lining the pond were floating happily on the surface, with all the water
UNDER the pond liner. Don't laugh - I saw it happen!
3) I don't think I'd find a pre-formed pond to the size I want, so this
sounds like too much disruption

Has anyone any practical experience of repairing a concrete pond?
Particularly 1) or 2)?
Baz

"Drakanthus" wrote in message
...

I think my mistake was buying a cheap polythene liner from B&Q.


NEVER use polythene liners!

1. they are not flexible ie not stretchy
2. they are not uv stable and have very short garden life

Butyl is 4*price but far better value.

pk

Xref: kermit uk.rec.gardening:148988

Thanks for all the feedback - a mine of info, as always.
Baz

"Drakanthus" wrote in message
2) Drain, then fit a pond liner into the nice neat hole
2) sounds better but I am worried about placing liner in a cement-lined
hole. I once saw rain get between liner and the wall of the pond.

The best solution would be to fix the leak, but how you go about finding
the
leak I haven't got a clue.

That's the easy bit, just let the pond drain and it will stop when it gets
just below the leak.
But what do you do with those 3ft+/- long Koi meanwhile?

Personally I'd go down the Butyl Liner route as if the concrete pond is
leaking in one spot it will soon leak in others. I've had a pond (with Koi)
made that way for over 20 years and no problems with liners coming away from
the cement skin underneath. You would only experience such a problem in very
heavy, pottery like, clay that would not allow any water to drain.

--
Bob

www.pooleygreengrowers.org.uk/ about an Allotment site in
Runnymede fighting for it's existence.