I chose this experiment for salt crystals because it was the easiest and fastest- growing one I could find at the time. I admit it - I'm impatient.
I'm hoping that next week we can try our hand at making sugar crystals (a.k.a. rock candy!), but there's a bit more involved with that - hopefully we'll have time for it.
For these salt crystals you'll need:
-Equal parts table salt, vinegar, and hot water (The recipe says you can also add an equal part of laundry bluing - whatever that is - but it's not necessary.)
-Toilet paper tube cut with fringes at top (see photo below).
Mix together salt, vinegar, and hot water in the plate.
Set toilet paper tube on plate.
Depending on your humidity, you should have some crystals within 24 hours.
Here is how ours looked after two days:
And after 7 days...
This Squidoo lens has an assortment of different "recipes" for growing all kinds of crystals. If you scroll down the page to the "YouTube Video of Salt Crystals", you can watch that to see a time-lapse version of the experiment we did. We were pleased with how ours turned out, but the one in the video is really neat - especially with the way they time-lapsed it. I showed it to our kids before actually doing the experiment, and they wanted to know if ours would grow that quickly. :)
This was a very worthwhile project - one that the kids really got into and looked forward to observing and touching everyday.