Ok, I guess I'm not understanding the purpose. I just called TSC and sure enough they have it. But they are telling me this stuff spreads and colors ALL the water. Don't I need something that will settle to the bottom where I think it's leaking and then get sucked out? I mean if it spreads how in the world will I know where the leak is? I need to plug the leak on the inside of the pond, not the outside, right?

How about mixing food coloring with condensed milk or something?