Its the Stress Coat. We had to stop using it at work because our MaRS system would get low on water in the sump and on a busy day we don't get a chance to fill it until we are closed, the water would foam up from the pump taking in air. It would foam all over the floor. Interesting to see, but a pain to clean up. Now we use AquaSafe, which doesn't foam nearly as badly.
Daniel