Herbert, here is an idea: Do a test on your water. Maybe it's a bit alcalic and that makes bubbles if it's mixed with acid like the ascorbic acid in X-tol. Take a glass of water and put a little citric acid in it and mix. See if you get bubbles. You can also use ph test paper. If you get bubbles or the indicator paper shows that your water is alcali, use destilled water when you develop film.(posted 8791 days ago)Hey! Why is X-tol made of ascorbic acid? How come that vitamin C can develop film? Hmmmm...