I remember this was one of the things I tried countless times as a kid. It never worked - the books showed these nice, clear crystals but all I ever got was a crust of dried salt and maybe one tiny crystal a few mm across.
I'm sure most of those "science for kids" book authors never tried a single one of their experiments.
my grandma saw and told me to use the rest of the string and sugar I had, enough for 12 more tries, and do them at once but in different areas of the house
only two actually grew but i learned the value of spreading risk and unknown unknowns ( much later, on reflection :) )
Made big rocks. https://en.wikipedia.org/wiki/Mother_liquor
They should at least recommend distilled water because tap water impurities vary greatly from place to place.
* Europe is Iodine Deficient (2003) https://www.thelancet.com/journals/lancet/article/PIIS0140-6...
* World map of iodine status (2021) https://www.ign.org/cm_data/IGN_Global_Scorecard_MAP_2021_SA...
* The Krakow Declaration on Iodine (2018) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6140595/
no.
> I don't think reasonably well-off people in developed countries need iodized salt, because we get enough iodine from our diets.
Depends very much on your diet. Lots of fish, milk, other animal products? Probably fine. Otherwise, maybe not so much.
On the other hand, there was one time I had to do a short no-iodine diet and it was pain in the ass. I had had to go out of the way to find non-iodized salt and good luck finding any pre-packaged food without iodized salt...
Most places either have soft water from their water supply, or people install a whole house water softener, if their water is hard enough to cause problems with mineralizing on dishes.
The salt for the whole house water softener would probably work, but the bags are pretty huge.
I am in the Bay Area. I bought some off Amazon no problem. It came from the US too.
> since we we generally don't have dishwashers with built in water softeners that need the salt.
Landlord installed a Bosch dishwasher, which has a water softener. The water is pretty hard (I can see by the shower faucet, and confirmed on the utility website). I'm assuming he didn't bother to import the dishwasher from Europe so it must be available in the US.
A quick check of Amazon.com [1] turned up a bunch of US-looking products, at least.
[1]: https://www.amazon.com/s?k=dishwasher+salt&crid=X6025PAVFBMS...
Plenty of non-american firms sell products in the US. Like... I don't know, Nestlé?
I watched the same Technology Connections video. He does mention Bosch dishwashers by name. Those are available in the US. It's just that people barely bother understanding how dishwashers work, let alone _very infrequently_ refilling the salt. Heck, people drive without checking tire pressures, dishwasher salt has no hope.
Not surprising that most stores don't bother. It lasts forever too.
I’m not sure about purity or anti-caking, although some brands are advertised as high purity. You can even get it delivered in the US: https://www.amazon.com/s?k=pool+salt
Perhaps look at the 20kg bags of food salt sold at wholesalers, which might not be iodised. I recall seeing one at a Chinese store, but I’m in New Zealand, so I’m unsure about the US.