im using that combo... ampro drybox + hungry hippo... registered a 0% humidity! oh dear i didnt know is better at 40%... anyway as a chem eng student, i dun think there are other chem release from calcium chloride and zeolite... mixing with moisture(H20)
SECTION 7 Storage and Special Information
Keep in a tightly closed container, stored in a cool, dry, ventilated area. Protect against physical damage. Moist calcium chloride and concentrated solutions can corrode steel. When exposed to the atmosphere, calcium chloride will absorb water and form a solution.
talk about paranoia, the thirsty hippo does come in a leak-proof container. i think we should concentrate on the topic here, we are talking about the effectiveness of thirsty hippos as a dessicator, not the potential hazards of it (which is inconsequential unless you tamper with the packaging).
so what's the verdict? isn't Nikonian Foo worried that his hygrometer may be giving the wrong reading?
I believe it depends on the size of the air-tight box.
I once poured too much silica gel into my dry box (abt a handful) and the built-in hygrometer registered 10%.
But after a few days, it went to 40-50%.
I did consider thirsty hippo, but it was
a) too big and will take up a lot of space in my dry box.
b) costly compared to a $3 bottle of silica gel
c) unable to re-use (silica gel can re-heat and re-use)
Mostly reason (a) is a big enough reason for me to rule it out.
As for dry cabinet, I think it's still costly if you don't have a lot of equipment.
If you only have 1 SLR with only 1-2 lens, it is cheaper to use drybox.
Unless you have lens worth thousands of $$$ like 80-200mm f/2.8..etc