It is a 1 L heavyweight pyrex glass beaker with about 800 ml of water held at 20 deg C. Food dye was added to the water for visibility. The PEPA is custom built and the prop mixer is an off the shelf item. The Scotch tape was the wide version taken from a 3 pack. The tape had just been opened. The mixer is clamped to a standard heavy duty ring stand. Power leads go to the rear. The prop mixer is on the base of the ring stand on the right in the second photo. Both photos are digital images that were cropped to size for uploading and to remove extraneous material such as the pump which can be partially seen on the left of the photos. A sheet of white backing paper was used to block shelves and other equipment such as pH meters, test solutions, more beakers and a timer. That was just clutter that was not needed for this purpose.

Is that enough information Ray? I can look up the time and date stamp of the images if you wish.

PE