bk,

I have a 1000-gallon or so concrete pond, also with a PVC pipe thru the wall
(I use it to go to the pump, which is in a separate hole just outside the
pond). Is there no way you can see or feel a leak on the outside, even if
you have to dig down? Mine has never leaked where the PVC pipe is, is why I
ask.

If I did have a leak there I'd drain down to the PVC pipe intake and fix
it - my pump intake is not at the lowest point but draws from about the 12"
level so that in case of some catastrophe the pump can never completely
empty the pond out.

But if you can't drain down to the pipe level, for the small amount of
hydraulic cement that'd be needed, I really wouldn't worry that it'd hurt
the fish. I've made minor repairs where some cement got into the pond but
in a 1000+ gallons it's not going to cause any harm. You can pre-roll the
hydraulic cement into several fairly thin strings, one at a time to place
around where the pipe joins the cement wall, and you'll get minimal amounts
dissolving immediately, and then what leaches out over a few days as it
cures completely can certainly be taken care of with just a bit of a water
change.

But be as sure as you can that's where your leak is, first!

Happy Ponding,
Tim C.

"bk" wrote in message
nk.net...
1200 gallon concrete pond with diamond brite finish. I believe I have a
slow
leak where I have a 1.5" pvc pipe cast thru the wall. I used to use this
for
plumbing, but now we just run a hose along the pond bottom tot he filter.
I'm sure I could plug it with hydrolic cement, but I don't want to hurt
the
fish.
Any suggestions?