Try the "leak" problem here...

[jatfla]

Since this is a do-it-yourself project for me, I'll try asking here. 

There is definitely a leak and I've let the water recede and it's stopped.  I've checked for roots (a very potential problem) and gotten down on my hands and knees, looking and feeling.  But I can't find anything.

I couldn't find it in the "search" but a while back someone described how to find leaks...something about bubbles.  Does anyone remember or have some other suggestions?

[mascot]

I don't know if anyone has answered this for you and it's been a while, but what I found out is that you can find a leak by letting the level drop to where it does for the leak (if it's not real low in the pond) and turn off the pump.  Then sprinkle something likefish food dust from the bottom of the bag and it will typically migrate towards the leak.

When I used to put beneficial bacteria in the pond (fine powder) it really showed me how fast the water was flowing and where the water flows most.

[spanishleprachaun]

  whole milk acts as a fantastic LEAK TRACER when going after a leak in side wall liner.

for one that you suspect is near the bottom-- and you just can't wait for pond to drain out... suck up the milk in a TURKEY BASTER...... slowly put the baster underwater.... and then slowly push out the milk near the underwater leak.
this allows for more direct concentration of milk near possible leak site.   You try and do this from surface of the water,. and the milk will difuse far to much by the time it sinks near the bottom

good luck !
c

[Feeaphinya]

All content is read in this thread. It was a new knowledge for me. I see it as a really useful thing.