what is your liner made from? Is it rubber? you can patch it.

The liner is rubber I guess. Thick pond liner I bought from justliners.com. Problem is that I don't know where the leak is, so I'd have to glue on a patch all around the circumference which is difficult with all the rocks etc. I was hoping I could get some stuff to paint on.

Lizm,
Was the pond running when this happened? Where is the pump located? How fast does the pond go down? Was the pond full of water all winter?
Mike

the pond was not running. It's a tiny pond, 3 ft. around, around 18 inches deep. It was full of water all winter with pump turned off. The pond goes down about six inches s day until it gets to about 5 inches from the bottom, then it stops leaking.

lizm
I am not an expert in this area but I am guessing that Mike may be thinking that you could have a leak in your pump tubing that is creating a syphon or just an overflow somehow. You neglected to say where the pump is located. Admittedly, a leak like this should be obvious by now, but if the pipe goes away from the edge or is burried deeply and you haven't looked, you might have missed it. In my clay soil I don't think I could lose water into the soil at your fast rate, but if you have sandy soil, who knows.

I got ahead of myself there. My initial point was that Mike and other wise diagnosticians will want ALL the info, and the sooner they get it, the faster they may help you.

Lizm,

Okay you are loosing about 26 gallons per day which is not a lot of water. Since you did not loose any water over the winter the leak has started since then. Is the pond totally in the ground or does some of it above ground? The next thing is to find out if Chas045 thinking is correct. I assume that the pump is in the pond. Lift the pump out of the pond. Refill the pond and see if it goes down. If it does go down then I would guess that some animal or bird made a hole. If a bird made the hole it would be fairly easy to find if it is an animal it could be almost anywhere.
Mike

I had the same problem a couple of weeks ago Lizm.Someone told me to fill up the pond to the top and turn off the pump and add a little bit of milk like a 1/4 of a cup around the edge of the pond and it will "stream" towards the leak. Thats how I found my leak.

Follow-Up: I used the milk and it told me nothing. Then I got a burst of energy and took the waterfall apart (this was heartbreaking because I'd spent hours last year bending in the most horrible positions gluing small rocks in strategic places so you couldn't see any part of the waterfall thing). Then, with the waterfall aside, I filled the pond up to see what would happen. Amazingly, it lost no water. So, even though I'd already determined that the waterfall was not leaking, something involved with the waterfall seems to make the water go out of the pond (grrrr!).

So I just set things up again, getting my poor husband to lift hideously heavy rocks to hide the waterfall again, andn I left it overnight last night. This morning the water was at the same level as 12 hours ago. Whew. I still have no idea what was causing the water to go out of the pond or if it will happen again! But for now, the pond is a "go" and I'm going to put my fish in. Will post photos later!
Thank you all for your help!

I wonder if someone here can help me: We have a Waterfall with a small pond at the bottom (4 feet wide, 3 feet long, 2 1/2 feet deep). It was installed by a landscaper about 4 years ago. Since last year the pond loses water fairly quickly (over night). We haven't turned the pump on all winter because we've been meaning to take out all the rocks and replace the liner.
I'm having some people working in the yard right now and they offered to fix the pond for me by using concrete and a liner. Does that sound right? From what I'm reading here it sounds like most of you just use a liner.
I'd really appreciate some advise on this - thank you! :)

how do i fix a hole in the hard plastic pond liner, i know where the hole is and i need something to fill the hole, there are fish already in the pond and it have been in for years.