I checked it for cracks as best I could, but I can't see anything.
But, it doesn't seem that the concrete is coated with anything, so
that could be it - is it still possible to coat it now? What kind of
acrylic is recommended for it?

"Sam Hopkins" wrote in message ...
True. Concrete is porous. If it's less than 4-5 inches thick it'll pass
water. They should have coated it with an acrylic admixture (is the cement
kinda shiny?) or had a liner under it.

"Bob H" wrote in message
...
I am reading the waterfall is leaking, closely inspect the waterfall
course,
It doesn't take much of a leak to drain a small pond in a few hours, if
you
have sandy soil you may never see water pooling....I presume the person
who
built the waterfall put in some kind of liner, if not it could just be
sinking into the ground through the cement or whatever they did put
in....it
takes a bit of detective work to find a leak, just remember you are
probably looking more for a steady drip than a geyser.

"D. Mahon" wrote in message
om...
I could really use some advice - we bought a house last year that has
a nice litle pond in the back - about 150 gallons, its one of the
plastic prefab ponds but with a nice little stone-and-cement placement
for it, and a waterfall. The problem we're having is that it keeps
draining when the waterfall is running. If the pump isn't on, the
water level stays fairly constant (a bit may evaporate, but none seems
to leak out). But when the pump is pumping and the waterfall is
going, it drains rapidly - if you turn it on in the morning, by night
say 1/3 to 1/2 of the water will be gone! There's no obvious leaks -
I've checked the tubing and as much of the inside of the cementy
waterfall-thing as I can, and there's nothing amiss that I can find.
There's also no evidence of a large amount of water draining into the
yard nearby. I don't knwo where else to check! I don't think that
much water would evaporate that quickly, especially as if you leave it
on overnight, it will drain at the same rate. It also seems to drain
faster if the pump is left on while it rains? Anyway, obviously I'm a
novice at this, so advice or suggestions would be greatly appreciated.