Dear Donia,
How often should I change the baking soda used to remove the smell of mildew from old photos?
Q. Dear Donia,
You once mentioned that for photos that smell mildewy (but show no evidence of mildew or mold) one option is to put the photos in a clean plastic storage container with bowls of baking soda and then put the top on the container. How often do we change the baking soda or how will we tell when the bowls should be changed?
A. Dear Helen,
Thank you for your excellent question! Frequency of change and the overall length of time to reduce the odor is always a tricky question. It is all based on how much baking soda you are using, how much surface area of the baking soda is exposed (shallow bowls expose more soda and work more efficiently), how many photos you have, and how smelly they are. In any event, I would follow the guidelines on the box which is to change the baking soda every 30 days. This should help to absorb odors more efficiently and help you complete the project faster.
You can also use activated charcoal that you can get at pet stores. Activated charcoal is used in fish tanks to keep the water clean and is also great at absorbing odors. You would use it in the same manner as baking soda but don't need to change it as often (only about every two months). You can also try the Gonzo Odor Eliminator Rocks that are available on Amazon. If you purchase a couple of these you can be recharging one while using the other. Again, change out every one to two months. Finally, I would avoid the odor absorbers you can find on Amazon or in the stores as these often have chemicals that release "pleasant" odors that can be damaging to your photographs. It is best to stick with baking soda or activated charcoal.