How much desiccant do you need? 

To use, simply choose English or SI units, and enter the following:
1 - The volume of the case
2 - The anticipated difference between the desired case humidity and the average ambient humidity
3 - The exchange rate for the case (# exchanges per day)
4 - The minimum time period (in days) before the gel will need to be maintained
5 - The maximum allowable deviation from the target RH%

How can I recondition my Silica Gel?
Silica gel can be reconditioned by adding moisture to it if it is too dry or by mixing it with bone dry silica gel if it is too moist. The calculator below shows how much water or dry gel you need to add. The dry gel can either be new unconditioned gel or used gel that has been dried in an oven at 240°F overnight. Gaylord Archival’s Reconditioning System has everything you need to easily recondition small or large quantities of gel.

Never add liquid water directly to silica gel. Use only properly designed reconditioning equipment.

To use, simply enter the following:
1 - The beginning weight (in grams) of the gel to be re-conditioned
2 - The beginning RH% of the gel to be re-conditioned
3 - The desired RH% of the gel once re-conditioned