Thank you all, for the valuable help available here. I am very new to this subject, no fishing experience. I got here because I have a 'pickle' of a problem. A deep pit, blasted in a sandstone bedrock is leaking water (maybe the blasting itself caused it), and I want to fix these leaks so I can store water in this pit. Right now it is full of water from rains, but will soon seep out. I am imagining to add some colloidal suspension that can go & clog the leakage points, or at least highlight them so I can fix it when this runs dry. Any thoughts to accomplish this? The photo of the wall, is a 187Kb file, attached here. Sorry it is large, but I don't have a URL.
The pit is huge, 60 ft. diameter, 42 ft deep. It was bedrock blasted hoping that water would seep in, but after-the-fact geophysical survey showed very little chance of water. So using it to just store rainwater during the rainy season, plus a nearby shallow stream, 8ft deep, I'm sure is letting some water seep in through the walls. The photo shows the pit in dry season, and the trickle of water is from the sand-stone itself, just a trickle. But 3 weeks of rain fills this huge pit and we can utilize it all, if it would contain it. As seen in the photo it runs dry after a month, while evaporation data should only deplete about a foot of water, in that time. Just seeking methods to find leaks, so we can point-fill them.
I wish there will be a water-based, inexpensive 'Stop-Leak', colloid solution or something. Best I have googled till now is benign chemical dye, like Brilliant Blue used in ice-cream, that I can hold on a string within a foot of the wall, and watch to see if a dye trace leads to an exit-point. repeat this every 6" around the circumference, and at every 6" level of water, all the way down as the well runs dry. A "Stop-Leak" will be more effective, if there was one.
Thanks a lot, anticipating some suggestions. Yes I should be careful not to seal the well-wall all the way to the top. Then, no water can come in. Except just the rainwater from the sky. I will determine what the water-table is during the rainy season, and seal the well maybe 5 or 10 ft. below that so it contains it to that level.