Pond Boss Forums GENERAL QUESTIONS Help The Case of the Disappearing Pond Tracing Dye

OK- so have been fighting a leak underneath my concrete capped natural overflow. Been using tracer dye to locate where leak may be coming from - have used concrete and bentonite to try and plug areas when I see tracing dye show up in the catch basin at the bottom of the capped wall.

My latest attempt was seveal bags of bentonite poured in over the back of a large rock where dye - when placed there - would come out at the bottom of catch basin. After doing that and putting dye in that area again - no more dye would show itself - but still had the same amount of leak showing up in the catch basin !!

So how can that be ? is the bentonite filtering out the dye as the water passes thru it ??

Like some thoughts on this - very baffling to me.