The emulsion I just made has been washed in purified water instead of tap water. I tested the tap water and found that adding a little silver nitrate causes significant cloudiness, the purified water does not (reverse osmosis water from a dispenser in the grocery store). I also discovered a few small light leaks reflecting in the bottom of the washing sink from the cealing, a couple of nail holes and a gap about 8" long, although difused, and about a 1/8" wide directly above the washing area, that could also be a big Duuuhhhhh...cause, we'll see. I will divide the emulsion in to two parts, leave one with no additives and add hardner to the other, coat some small plates and put a penny on top and expose to light and develop. If there is still a problem, try one more time with the leak covered up.